Absorbent article which maintains or improves skin health

ABSTRACT

An absorbent article includes a vapor permeable backsheet, a liquid permeable topsheet positioned in facing relation with the backsheet; and an absorbent body located between the backsheet and the topsheet. The absorbent body may include multiple zones of high air permeability. The absorbent article may also include a ventilation layer between the absorbent body and the backsheet and a surge management layer between the absorbent body and the topsheet. The article exhibits improved air exchange within the article during use. As a result, the article maintains the temperature and exhibits substantially reduced levels of hydration of the wearer&#39;s skin when in use which renders the skin less susceptible to the viability of microorganisms. The absorbent article may further include lotion formulations and/or treatment compositions thereon for maintaining or improving skin health.

This application is a divisional of application Ser. No. 09/379,431entitled ABSORBENT ARTICLE WHICH MAINTAINS OR IMPROVES SKIN HEALTH andfiled in the U.S. Patent and Trademark Office on Aug. 23, 1999. Theentirety of application Ser. No. 09/379,431 is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an absorbent article for absorbing bodyfluids and exudates, such as urine. More particularly, the presentinvention relates to absorbent garments, such as disposable diapers andadult incontinence garments, which are configured to absorb bodyexudates while maintaining or improving the health of the wearer's skin.

2. Description of the Related Art

Many known absorbent article configurations employ absorbent materialslocated between a liquid pervious topsheet and a liquid impermeablebacksheet. Such backsheets are well suited to prevent the migration ofliquid waste from the absorbent materials to the outer garments of awearer. Unfortunately, the use of such articles and, in particular, suchartides which indude a liquid and vapor impermeable backsheet can resultin a high degree of humidity within the diaper when in use which mayincrease the temperature of the wearer's skin and result in relativelyhigh skin hydration levels. Such conditions can lead to a reduction inthe health of the wearer's skin. For example, the occlusive, moistenvironment inside absorbent articles incorporating such backsheets canpromote the viability of microorganisms, including Candida albicans,which can undesirably lead to the onset of dermatitis such as what iscommonly referred to as diaper rash.

Moreover, the liquid pervious topsheets on such articles have typicallybeen constructed of nonwoven materials such as spunbond polyolefinmaterials. Unfortunately, such materials do not always provide a soft,nonabrasive contact with the skin. In particular, during continuous useof absorbent articles containing such topsheets, the wearer's skin canbecome quite irritated and red particularly in the presence of urine andfeces. The abrasion resulting from such topsheets and the presence ofurine and feces can also undesirably lead to the onset of dermatitis.

Diaper dermatitis can afflict almost every infant at some time duringthe diaper wearing years. The most severe form of this condition isusually caused by secondary infection with the fungi Candida albicans.Although other factors influence the pathogenesis of this fungi, onecritical factor is the relative humidity within the diaper which isdirectly related to the occlusion or semi-occlusion of the diaper area.

In order to reduce the humidity level within diapers, breathable polymerfilms have been employed as outer covers for absorbent garments, such asdisposable diapers. The breathable films are typically constructed withmicropores to provide desired levels of liquid impermeability and airpermeability. Other disposable diaper designs have been arranged toprovide breathable regions in the form of breathable panels orperforated regions in otherwise vapor-impermeable backsheets to helpventilate the garment.

Moreover, to prevent body exudates from contacting the wearer's skin,the caregiver often applies skin protective products directly to theskin of the wearer before positioning the article on the wearer. Suchproducts have included petrolatum, mineral oil, talc, corn starch, orvarious other commercially available rash creams or lotions. Thisprocedure typically involves the caregiver applying the products totheir hand and then transferring the products to the wearer's skin.

To eliminate the caregiver from contacting the products and to reduceskin abrasion and improve skin health, some conventional absorbentarticles have included lotion formulations applied to the topsheet suchthat, in use, the formulations transfer to the skin or provide lubricitythereby reducing the friction between the topsheet and the skin.However, conventional lotion formulations have been unstable and tendedto migrate away from the surface of the topsheet into the topsheet andabsorbent core of the absorbent articles leaving less on the surface totransfer to the skin or provide the reduced abrasion. This migrationproblem is particularly evident at higher temperatures such as those atthe skin surface in use or those in typical storage conditions in warmclimates.

Conventional absorbent articles, such as those described above, have notbeen completely satisfactory. For example, articles which employperforated films or breathable panels can exhibit excessive leakage ofliquids from the article and can excessively soil the wearer's outergarments in the regions of the perforations or panels. In addition, whenthe absorbent material of the article becomes loaded with liquid, thewet absorbent can block the escape of moisture from the wearer's skin.Such absorbent garment designs have not been able to maintain a highlevel of breathability when wet to sufficiently reduce the hydration ofthe wearer's skin.

Moreover, lotions which have been incorporated on the topsheets of sucharticles have migrated such that a less effective amount has beenapplied to the wearer's skin or been located between the skin and thetopsheet in use. Thus, large amounts of such lotions have been requiredto be added to the topsheet to deliver the skin benefit. As a result,the wearer's skin has remained susceptible to rashes, abrasion andirritation. Accordingly, there remains a need for absorbent articleswhich maintain or improve skin health.

SUMMARY OF THE INVENTION

In response to the difficulties and problems discussed above, newdisposable absorbent articles which maintain or improve the health ofthe wearer's skin have been discovered. Such absorbent articles may havea high air exchange rate when wet, maintain skin temperature when wet,have reduced levels of skin hydration, include a lotion formulation ortreatment composition which provides a skin health benefit, and/or havea reduced viability of microorganisms.

When employed in the present disclosure, the terms “comprises”,“comprising” and other derivatives from the root term “comprise” areintended to be open-ended terms that specify the presence of any statedfeatures, elements, integers, steps, or components, but do not precludethe presence or addition of one or more other features, elements,integers, steps, components, or groups thereof.

As used herein, reference to “air exchange” refers to the transfer ofair and, in particular, humid air from the interior of an absorbentarticle, when in use on a wearer, to the exterior of the absorbentarticle (ambient atmosphere) which allows drier ambient air to move intothe absorbent article.

As used herein, a substantially liquid impermeable material isconstructed to provide a hydrohead of at least about 60 cm(centimeters), desirably at least about 80 cm, and more desirably atleast about 100 cm. A suitable technique for determining the hydroheadvalue is the Hydrostatic Pressure Test which is described in furtherdetail herein below.

As used herein, a substantially vapor permeable material is constructedto provide a water vapor transmission rate (WVTR) of at least about 100g/sq.m/24 hr, desirably at least about 250 g/sq.m/24 hr, and moredesirably at least about 500 g/sq.m/24 hr. A suitable technique fordetermining the WVTR value is the Water Vapor Transmission Rate Testwhich is described in further detail herein below.

As used herein, the term “viscosity” refers to the viscosity incentipoise determined according to ASTM D3236, entitled “Standard TestMethod for Apparent Viscosity of Hot Melt Adhesives and CoatingMaterials.”

As used herein, the phrase “melting point” refers to the temperature atwhich the majority of the melting occurs, it being recognized thatmelting actually occurs over a range of temperatures.

As used herein, the phrase “melt point viscosity” refers to theviscosity of the formulation at the temperature at which the majority ofthe melting occurs, it being recognized that melting actually occursover a range of temperatures.

As used herein, the phrase “penetration hardness” refers to the needlepenetration in millimeters according to ASTM D 1321, “Needle Penetrationof Petroleum Waxes.” Lower needle penetration hardness values correspondto harder materials.

As used herein, the term “z-direction migration loss” refers to thevalue obtained when subjecting an absorbent article having a lotionformulation on the bodyfacing surface thereof to the Z-Direction LotionMigration Test set forth below.

As used herein, the term “cd-direction migration loss” refers to thevalue obtained when subjecting an absorbent article having a lotionformulation on the bodyfacing surface thereof to the CD-Direction LotionMigration Test set forth below.

In one aspect, the present invention relates to an absorbent articlewhich comprises an absorbent, a front waist section, a rear waistsection and an intermediate section which interconnects the front andrear waist sections. The absorbent article defines a Wet Air ExchangeRate of at least about 190 cubic centimeters per minute calculatedaccording to the Tracer Gas Test set forth herein. In a particularembodiment, the article defines a Wet Air Exchange Rate of at leastabout 200, desirably at least about 225 and more desirably at leastabout 250 cubic centimeters per minute calculated according to theTracer Gas Test. The absorbent article may further define a Dry AirExchange Rate of at least about 525 cubic centimeters per minutecalculated according to the Tracer Gas Test and/or a Skin HydrationValue of less than about 18 grams per square meter per hour calculatedaccording to a Skin Hydration Test set forth herein.

In another aspect, the present invention relates to a disposableabsorbent article which comprises an absorbent, a front waist section, arear waist section and an intermediate section which interconnects thefront and rear waist sections. The absorbent article defines a SkinHydration Value of less than about 18 grams per square meter per hourcalculated according to the Skin Hydration Test set forth herein. In aparticular embodiment, the absorbent article may define a Skin HydrationValue of less than about 15, desirably less than about 12 and moredesirably less than about 10 grams per square meter per hour calculatedaccording to the Skin Hydration Test. The absorbent article may furtherdefine a Wet Air Exchange Rate of at least about 190 cubic centimetersper minute and/or a Dry Air Exchange Rate of at least about 525 cubiccentimeters per minute calculated according to the Tracer Gas Test asset forth herein.

In another aspect, the present invention relates to a disposableabsorbent article which defines a front waist section, a rear waistsection, and an intermediate section which interconnects the front andrear waist sections. The absorbent article includes a) a vapor permeablebacksheet which defines a Water Vapor Transmission Rate of at leastabout 1000 grams per square meter per 24 hours calculated according to aWater Vapor Transmission Test as set forth herein; b) a liquid permeabletopsheet which is positioned in facing relation with the backsheet; andc) an absorbent body located between the backsheet and the topsheetwhich may define multiple zones of high air permeability for improvedair exchange. In a particular embodiment, the zones of high airpermeability in the absorbent body define a Frazier Porosity which is atleast about 10 percent greater than a Frazier Porosity of portions ofthe absorbent body adjacent to the zones of high air permeability. Theabsorbent article may further include a ventilation layer locatedbetween the backsheet and the absorbent body.

In still another aspect, the present invention relates to a disposableabsorbent article which defines a front waist section, a rear waistsection, and an intermediate section which interconnects the front andrear waist sections. The absorbent article includes a) a vaporpermeable, liquid impermeable backsheet which defines a Water VaporTransmission Rate of at least about 1000 grams per square meter per 24hours calculated according to a Water Vapor Transmission Test as setforth herein; b) a liquid permeable topsheet which is positioned infacing relation with the backsheet; c) an absorbent body located betweenthe backsheet and the topsheet; d) a ventilation layer located betweenthe backsheet and the absorbent body; and e) a surge management layerlocated between the topsheet and the absorbent body. In a particularembodiment, the absorbent body of the absorbent article includes aplurality of zones of high air permeability for improved air exchangewhich define a Frazier Porosity which is at least about 10 percentgreater than a Frazier Porosity of portions of the absorbent bodyadjacent to the zones.

In yet another aspect, the present invention relates to a disposableabsorbent article which includes an absorbent, a front waist section, arear waist section and an intermediate section which interconnects thefront and rear waist sections. The absorbent artide defines a C.albicans viability which is less than about 85 percent of the C.albicans viability of a control calculated according to a C. albicansViability Test as set forth herein. In a particular embodiment, the C.albicans viability is less than about 80 percent and desirably less thanabout 60 percent of the C. albicans viability of the control calculatedaccording to the C. albicans Viability Test. The absorbent article mayfurther define a Wet Air Exchange Rate of at least about 190 cubiccentimeters per minute and/or a Dry Air Exchange Rate of at least about525 cubic centimeters per minute calculated according to the Tracer GasTest as set forth herein and/or a Skin Hydration Value of less thanabout 18 grams per square meter per hour calculated according to theSkin Hydration Test set forth herein.

In another aspect, the present invention relates to a disposableabsorbent article which comprises an absorbent, a front waist section, arear waist section and an intermediate section which interconnects thefront and rear waist sections. The absorbent article defines a Wet SkinTemperature/Dry Skin Temperature Ratio of no more than about 1.010calculated according to a Skin Temperature Test as set forth herein. Inparticular embodiments, the absorbent article defines a Wet SkinTemperature/Dry Skin Temperature Ratio of no more than about 1.005,desirably no more than about 1.000, more desirably no more than about0.995, and even more desirably no more than about 0.990 calculatedaccording to the Skin Temperature Test. The absorbent article mayfurther define a Wet Air Exchange Rate of at least about 190 cubiccentimeters per minute and/or a Dry Air Exchange Rate of at least about525 cubic centimeters per minute calculated according to the Tracer GasTest as set forth herein and/or a Skin Hydration Value of less thanabout 18 grams per square meter per hour calculated according to theSkin Hydration Test set forth herein.

In still another aspect, the present invention resides in an absorbentarticle having a topsheet which includes a lotion formulation ortreatment composition on the outer bodyfacing surface thereof. In aparticular embodiment, the topsheet includes a lotion formulationcomprising from about 5 to about 95 weight percent of an emollient, fromabout 5 to about 95 weight percent of a wax, and, optionally, from about0.1 to about 25 weight percent of a viscosity enhancer. The lotionformulation may be applied by known methods in the art such as spraying,slot coating or printing to the topsheet at a temperature no more thanabout 10° C. above a melting point of the lotion formulation to reducemigration of the lotion formulation on the topsheet.

In some embodiments, the emollient is selected from the group consistingof oils, esters, glycerol esters, ethers, alkoxylated carboxylic acids,alkoxylated alcohols, fatty alcohols and mixtures thereof. Moreover, insome embodiments, the wax is selected from the group consisting ofanimal based waxes, vegetable based waxes, mineral based waxes, siliconebased waxes and mixtures thereof all of which may be natural orsynthetic.

In a particular aspect, the lotion formulation includes from about 5 toabout 95 weight percent of petrolatum, from about 5 to about 95 weightpercent of a wax selected from the group consisting of animal basedwaxes, vegetable based waxes, mineral based waxes, silicone based waxesand mixtures thereof all of which may be natural or synthetic and fromabout 0.1 to about 25 weight percent of a polyolefin resin all based onthe total weight of the lotion formulation.

In still another aspect, the present invention resides in an absorbentarticle having a topsheet which includes a treatment composition on theouter bodyfacing surface thereof. The treatment composition includes asurfactant and a skin health benefit agent, preferably as an emulsionsuch as an oil-in-water emulsion. The skin health benefit agent mayinclude zinc compositions. The treatment composition may also include aprotein such as silk proteins like sericin.

The various aspects of the present invention advantageously provide anabsorbent article with maintain or improve the health of the wearer'sskin. For example, such improved absorbent articles may exhibitsubstantially reduced levels of hydration of the wearer's skin when inuse compared to conventional absorbent articles. The reduced level ofskin hydration promotes drier, more comfortable skin and renders theskin less susceptible to the viability of microorganisms. Thus, wearer'sof absorbent articles made according to the present invention havereduced skin hydration and more constant skin temperatures in use whichcan lead to a reduction in the incidence of skin irritation and rash.

Moreover, in particular embodiments, the lotionized or treated topsheetprovides a soft, smooth contact with the wearer's skin and reducedlevels of skin irritation. Moreover, because the lotion formulationsapplied to the topsheet are more stable and have a higher viscosity thanconventional lotion formulations, particularly at higher temperatures, agreater percentage of the added lotion remains on the surface of thetopsheet where it can readily contact and transfer to the wearer's skinto provide the benefit. Further, if desired, a lower amount of thelotion formulation can be added to the topsheet to provide the samebenefit at a lower cost due to the localization of the lotion at thesurface of the topsheet. As a result, the skin of the wearers of theabsorbent articles of the present invention may be less susceptible torashes, abrasion and irritation.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood and further advantages willbecome apparent when reference is made to the following detaileddescription of the invention and the accompanying drawings, in which:

FIG. 1 representatively shows a partially cutaway, top plan view of anabsorbent article according to one embodiment of the invention;

FIG. 2 representatively shows a sectional view of the absorbent articleof FIG. 1 taken along line 2—2.

FIG. 3 representatively shows a partially cutaway, top plan view of anabsorbent body for an absorbent article according to another embodimentof the invention;

FIG. 4 representatively shows a sectional view of the absorbent body ofFIG. 3 taken along line 4—4.

FIG. 5 representatively shows a partially cutaway, top plan view of anabsorbent body for an absorbent article according to another embodimentof the invention;

FIG. 6 representatively shows a sectional view of the absorbent body ofFIG. 5 taken along line 6—6;

FIG. 7 representatively shows a graph of the data from Example 15 andComparative Example 6;

FIG. 8 representatively shows the test apparatus for the LotionMigration Test set forth herein; and

FIGS. 9-13 representatively show the results from Examples 17-21.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description will be made in the context of adisposable diaper article which is adapted to be worn by infants aboutthe lower torso. It is readily apparent, however, that the absorbentarticle of the present invention would also be suitable for use as othertypes of absorbent articles, such as feminine care pads, incontinencegarments, training pants, and the like.

The absorbent articles of the present invention advantageously maintainor improve the health of the wearer's skin. For example, the absorbentarticles may exhibit a substantially reduced level of hydration of thewearer's skin in use when compared to conventional absorbent articles.The absorbent articles of the present invention may further maintain amore constant temperature of the wearer's skin when wet when compared toconventional absorbent articles. Thus, wearer's of absorbent articles ofthe different aspects of the present invention have reduced skinhydration which renders the skin less susceptible to the viability ofmicroorganisms which can lead to a reduction in the incidence of skinirritation and rash. The absorbent articles of the present invention mayalso deliver a lotion or other skin health benefit agent to the wearer'sskin to provide improved skin health in use when compared toconventional absorbent articles.

It has been discovered that the ability of the absorbent articles of thepresent invention to exhibit a low level of hydration on the wearer'sskin during use depends, at least in part, on the ability of theabsorbent article to achieve a high rate of air exchange within thearticle. Moreover, it has been further discovered that the achievementof such low levels of skin hydration also depends on the ability of thearticle to maintain the high rate of air exchange and a more constantskin temperature even when wet.

The ability of an absorbent article to achieve high rates of airexchange both when dry and when wet has, for the purposes of thisapplication, been quantified as the Dry Air Exchange Rate, the Wet AirExchange Rate and the Wet Air Exchange Rate/Dry Air Exchange Rate ratioas determined according to the Tracer Gas Test set forth below. Briefly,the Tracer Gas Test involves injecting a tracer gas at a constant rateinside the absorbent article next to the skin of the wearer while thearticle is being worn. Simultaneously, the concentration of the tracergas in the air space between the article and the wearer is measured bywithdrawing a sample at the same constant rate as the injection. The airexchange is then determined based on mass balances of the tracer gas andthe air within the space in question.

To achieve the desired low levels of skin hydration, the absorbentarticles of the different. aspects of the present invention may beconstructed to define a Wet Air Exchange Rate of at least about 190cubic centimeters per minute, generally at least about 200 cubiccentimeters per minute, desirably at least about 225 cubic centimetersper minute, more desirably at least about 250 cubic centimeters perminute, and even more desirably at least about 300 cubic centimeters perminute. For example, the absorbent articles may define a Wet AirExchange Rate of from about 175 to about 1500 cubic centimeters perminute and desirably from about 225 to about 1500 cubic centimeters perminute. Absorbent articles which exhibit Wet Air Exchange Rates lessthan those above do not allow a sufficient amount of air exchange andundesirably result in increased levels of skin hydration. Such increasedlevels of skin hydration can render the skin more susceptible to theviability of microorganisms which can undesirably lead to an increase inthe incidence of skin irritation and rash.

The absorbent articles of the different aspects of the present inventionmay further be constructed to define a Dry Air Exchange Rate of at leastabout 525 cubic centimeters per minute, generally at least about 575cubic centimeters per minute, desirably at least about 625 cubiccentimeters per minute, more desirably at least about 675 cubiccentimeters per minute, and even more desirably at least about 750 cubiccentimeters per minute for improved performance. For example, theabsorbent articles may define a Dry Air Exchange Rate of from about 525to about 2500 cubic centimeters per minute and desirably from about 575to about 2500 cubic centimeters per minute. Absorbent articles whichexhibit Dry Air Exchange Rates less than those above do not allow asufficient amount of air exchange and undesirably result in increasedlevels of skin hydration. Such increased levels of skin hydration canrender the skin more susceptible to the growth of microorganisms whichcan undesirably lead to an increase in the incidence of skin irritationand rash.

The absorbent articles of the different aspects of the present inventionmay further be constructed to define a Wet Air Exchange Rate/Dry AirExchange Rate ratio of at least about 0.20, generally at least about0.23, desirably at least about 0.27, and more desirably at least about0.30 for improved performance. For example, the absorbent articles maydefine a Wet Air Exchange Rate/Dry Air Exchange Rate ratio of from about0.20 to about 1 and desirably from about 0.23 to about 1 for improvedperformance.

The ability of an absorbent article to maintain a more constant skintemperature when wet has, for the purposes of this application, beenquantified as the Wet Skin Temperature/Dry Skin Temperature ratio asdetermined according to the Skin Temperature Test set forth below.Briefly, the Skin Temperature Test involves placing the article to betested about the forearms of test participants and measuring thetemperature of the skin underneath the article before and after thearticle is wetted with a known amount of saline solution. The Dry SkinTemperature is recorded after the dry article has been worn for five (5)minutes. The article is then wetted and the Wet Skin Temperature isrecorded after the wetted article has been worn for one hundred twenty(120) minutes.

The absorbent articles of the different aspects of the present inventionmay be constructed to define Wet Skin Temperature/Dry Skin Temperatureratio of no more than about 1.010, generally no more than about 1.005,desirably no more than about 1.000, more desirably no more than about0.995, and even more desirably no more than about 0.990 for improvedperformance. For example, the absorbent articles may define a Wet SkinTemperature/Dry Skin Temperature ratio of from about 0.950 to about1.010 and desirably from about 0.970 to about 1.005 for improvedperformance. Absorbent articles which exhibit Wet Skin Temperature/DrySkin Temperature ratios greater than those above do not maintain skintemperature when wet which can render the skin more susceptible to theviability of microorganisms which can undesirably lead to an increase inthe incidence of skin irritation and rash.

The ability of the absorbent articles of the present invention toexhibit more constant skin temperature and high levels of air exchangerate both when dry and when wet has led to reduced levels of skinhydration. The ability of an absorbent article to achieve a low level ofskin hydration has, for the purposes of this application, beenquantified as the Skin Hydration Value. As used herein, the term “SkinHydration Value” refers to the value determined according to the SkinHydration Test set forth below. In general, the Skin Hydration Value isdetermined by measuring the evaporative water loss on the skin of testsubjects after wearing the wetted absorbent article for a set period oftime.

In particular embodiments, the absorbent articles of the differentaspects of the present invention may be constructed to define a SkinHydration Value of less than about 18 grams per square meter per hour,generally less than about 15 grams per square meter per hour, desirablyless than about 12 grams per square meter per hour, more desirably lessthan about 10 grams per square meter per hour, even more desirably lessthan about 8 grams per square meter per hour, and yet even moredesirably less than about 5 grams per square meter per hour for improvedperformance. For example, the absorbent articles of the presentinvention may define a Skin Hydration Value of from about 0.1 to about18 grams per square meter per hour and desirably from about 0.1 to about12 grams per square meter per hour. Absorbent articles which exhibitSkin Hydration Values greater than those above can render the skin moresusceptible to the growth of microorganisms which can undesirably leadto an increase in the incidence of skin irritation and rash.

The absorbent articles of the present invention may further exhibitreduced viability rates of microorganisms which can lead to a reductionin skin irritation. It is hypothesized that the reduced viability ofmicroorganisms is a direct result of the increased breathability and airexchange within the articles of the present invention. The ability of anabsorbent article to achieve a low rate of viability of microorganismshas, for the purposes of this application, been quantified as the C.albicans viability value since it is hypothesized that the presence ofCandida albicans is directly related to the incidence of irritation and,in particular, rash. As used herein, the term “C. albicans viability”refers to the value determined according to the Candida albicansViability Test set forth below. The Candida albicans Viability Test, ingeneral, is a comparison of the C. albicans viability under a patch ofthe test absorbent article to the C. albicans viability under a controlpatch from a conventional absorbent article having a nonbreathable outercover, i.e. an outer cover having a WVTR of less than 100 grams persquare meter per 24 hours.

In particular embodiments, the absorbent articles of the differentaspects of the present invention may be constructed to define a C.albicans viability of less than about 85 percent, generally less thanabout 80 percent, desirably less than about 60 percent, more desirablyless than about 40 percent, and even more desirably less than about 20percent of the C. albicans viability of the control for improvedperformance. For example, the absorbent articles of the presentinvention may define a C. albicans viability of less than about 2.5,desirably less than about 2.0, and more desirably less than about 1.75log of C. albicans colony forming units when inoculated with asuspension of about 5-7 log of C. albicans colony forming unitsaccording to the Candida albicans Viability Test. Absorbent articleswhich exhibit C. albicans viability values greater than those above canundesirably lead to an increase in the incidence of skin irritation andrash. Desirably, the above C. albicans viability values are obtainedwithout the incorporation of antimicrobial agents into the absorbentarticles which can be perceived by consumers in a negative manner.

It has been discovered that the maintenance or improvement in the healthof the wearer's skin can be achieved by selecting absorbent articleconstructions having a combination of one or more of the above-describedproperties. For example, a given level of acceptable, improvedperformance may be achieved by employing an absorbent article whichexhibits a Dry Air Exchange Rate of at least about 525 cubic centimetersper minute and a Wet Air Exchange Rate of at least about 175 cubiccentimeters per minute, and desirably a Dry Air Exchange Rate of atleast about 675 cubic centimeters per minute and a Wet Air Exchange Rateof at least about 200 cubic centimeters per minute. Alternatively,improved performance can be achieved by employing an absorbent articlewhich exhibits a Wet Air Exchange Rate of at least about 175 cubiccentimeters per minute and a Skin Hydration Value of less than about 18grams per square meter per hour, and desirably a Wet Air Exchange Rateof at least about 200 cubic centimeters per minute and a Skin HydrationValue of less than about 12 grams per square meter per hour.

Still further, it has been discovered that improved performance can beachieved by employing absorbent articles having a Dry Air Exchange Rateof at least about 525 cubic centimeters per minute and a Wet AirExchange Rate/Dry Air Exchange Rate ratio of at least about 0.20 anddesirably a Dry Air Exchange Rate of at least about 625 cubiccentimeters per minute and a Wet Air Exchange Rate/Dry Air Exchange Rateratio of at least about 0.23.

Examples of suitable constructions of absorbent articles for use in thepresent invention are described below and representatively illustratedin FIGS. 1-6. FIG. 1 is a representative plan view of an integralabsorbent garment article, such as disposable diaper 10, of the presentinvention in its flat-out, uncontracted state (i.e., with all elasticinduced gathering and contraction removed). Portions of the structureare partially cut away to more clearly show the interior construction ofdiaper 10, and the surface of the diaper which contacts the wearer isfacing the viewer. FIG. 2 representatively shows a sectional view of theabsorbent article of FIG. 1 taken along line 2—2. With reference toFIGS. 1 and 2, the disposable diaper 10 generally defines a front waistsection 12, a rear waist section 14, and an intermediate section 16which interconnects the front and rear waist sections. The front andrear waist sections include the general portions of the article whichare constructed to extend substantially over the wearer's front and rearabdominal regions, respectively, during use. The intermediate section ofthe article includes the general portion of the article which isconstructed to extend through the wearer's crotch region between thelegs.

The absorbent article includes a vapor permeable backsheet 20, a liquidpermeable topsheet 22 positioned in facing relation with the backsheet20, and an absorbent body 24, such as an absorbent pad, which is locatedbetween the backsheet 20 and the topsheet 22. The backsheet 20 defines alength and a width which, in the illustrated embodiment, coincide withthe length and width of the diaper 10. The absorbent body 24 generallydefines a length and width which are less than the length and width ofthe backsheet 20, respectively. Thus , marginal portions of the diaper10, such as marginal sections of the backsheet 20, may extend past theterminal edges of the absorbent body 24. In the illustrated embodiments,for example, the backsheet 20 extends outwardly beyond the terminalmarginal edges of the absorbent body 24 to form side margins and endmargins of the diaper 10. The topsheet 22 is generally coextensive withthe backsheet 20 but may optionally cover an area which is larger orsmaller than the area of the backsheet 20, as desired. The backsheet 20and topsheet 22 are intended to face the garment and body of the wearer,respectively, while in use.

The permeability of the backsheet is configured to enhance thebreathability of the absorbent article to reduce the hydration of thewearer's skin during use without allowing excessive condensation ofvapor, such as urine, on the garment facing surface of the backsheet 20which can undesirably dampen the wearer's clothes.

To provide improved fit and to help reduce leakage of body exudates fromthe diaper 10, the diaper side margins and end margins may beelasticized with suitable elastic members, such as single or multiplestrands of elastic. The elastic strands may be composed of natural orsynthetic rubber and may optionally be heat shrinkable or heatelasticizable. For example, as representatively illustrated in FIGS. 1and 2, the diaper 10 may include leg elastics 26 which are constructedto operably gather and shirr the side margins of the diaper 10 toprovide elasticized leg bands which can closely fit around the legs ofthe wearer to reduce leakage and provide improved comfort andappearance. Similarly, waist elastics 28 can be employed to elasticizethe end margins of the diaper 10 to provide elasticized waists. Thewaist elastics are configured to operably gather and shirr the waistsections to provide a resilient, comfortably close fit around the waistof the wearer. In the illustrated embodiments, the elastic members areillustrated in their uncontracted, stretched condition for the purposeof clarity.

Fastening means, such as hook and loop fasteners 30, are employed tosecure the diaper on a wearer. Alternatively, other fastening means,such as buttons, pins, snaps, adhesive tape fasteners, cohesives,mushroom-and-loop fasteners, or the like, may be employed.

The diaper 10 may further include other layers between the absorbentbody 24 and the topsheet 22 or backsheet 20. For example, asrepresentatively illustrated in FIGS. 1 and 2, the diaper 10 may includea ventilation layer 32 located between the absorbent body 24 and thebacksheet 20 to insulate the backsheet 20 from the absorbent body 24 toimprove air circulation and effectively reduce the dampness of thegarment facing surface of the backsheet 20. The ventilation layer 32 mayalso assist in distributing fluid exudates to portions of the absorbentbody 24 which do not directly receive the insult. The diaper 10 may alsoinclude a surge management layer 34 located between the topsheet 22 andthe absorbent body 24 to prevent pooling of the fluid exudates andfurther improve air exchange and distribution of the fluid exudateswithin the diaper 10.

The diaper 10 may be of various suitable shapes. For example, the diapermay have an overall rectangular shape, T-shape or an approximatelyhour-glass shape. In the shown embodiment, the diaper 10 has a generallyI-shape. The diaper 10 further defines a longitudinal direction 36 and alateral direction 38. Other suitable diaper components which may beincorporated on absorbent articles of the present invention includecontainment flaps, waist flaps, elastomeric side panels, and the likewhich are generally known to those skilled in the art.

Examples of diaper configurations suitable for use in connection withthe instant application which may include other diaper componentssuitable for use on diapers are described in U.S. Pat. No. 4,798,603issued Jan. 17, 1989, to Meyer et al.; U.S. Pat. No. 5,176,668 issuedJan. 5, 1993, to Bernardin; U.S. Pat. No. 5,176,672 issued Jan. 5, 1993,to Bruemmer et al.; U.S. Pat. No. 5,192,606 issued Mar. 9, 1993, toProxmire et al., and U.S. Pat. No. 5,509,915 issued Apr. 23, 1996 toHanson et al., the disclosures of which are herein incorporated byreference.

The various components of the diaper 10 are integrally assembledtogether employing various types of suitable attachment means, such asadhesive, sonic bonds, thermal bonds or combinations thereof. In theshown embodiment, for example, the topsheet 22 and backsheet 20 areassembled to each other and to the absorbent body 24 with lines ofadhesive, such as a hot melt, pressure-sensitive adhesive. Similarly,other diaper components, such as the elastic members 26 and 28,fastening members 30, and ventilation and surge layers 32 and 34 may beassembled into the diaper article by employing the above-identifiedattachment mechanisms.

The backsheet 20 of the diaper 10, as representatively illustrated inFIGS. 1 and 2, is composed of a substantially vapor permeable material.The backsheet 20 is generally constructed to be permeable to at leastwater vapor and has a water vapor transmission rate of at least about1000 g/sq.m/24 hr., desirably at least about 1500 g/sq.m/24 hr, moredesirably at least about 2000 g/sq.m/24 hr., and even more desirably atleast about 3000 g/sq.m/24. For example, the backsheet 20 may define awater vapor transmission rate of from about 1000 to about 6000 g/sq.m/24hr. Materials which have a water vapor transmission rate less than thoseabove do not allow a sufficient amount of air exchange and undesirablyresult in increased levels of skin hydration.

The backsheet 20 is also desirably substantially liquid impermeable. Forexample, the backsheet may be constructed to provide a hydrohead valueof at least about 60 cm, desirably at least about 80 cm, and moredesirably at least about 100 cm when subjected to the HydrostaticPressure Test. Materials which have hydrohead values less than thoseabove undesirably result in the strike through of liquids, such asurine, during use. Such fluid strike through can undesirably result in adamp, clammy feeling on the backsheet 20 during use.

The backsheet 20 may be composed of any suitable materials which eitherdirectly provide the above desired levels of liquid impermeability andair permeability or, in the alternative, materials which can be modifiedor treated in some manner to provide such levels. In one embodiment, thebacksheet 20 may be a nonwoven fibrous web constructed to provide therequired level of liquid impermeability. For example, a nonwoven webcomposed of spunbonded or meltblown polymer fibers may be selectivelytreated with a water repellent coating or laminated with a liquidimpermeable, vapor permeable polymer film to provide the backsheet 20.In a particular embodiment of the invention, the backsheet 20 maycomprise a nonwoven web composed of a plurality of randomly depositedhydrophobic thermoplastic meltblown fibers which are sufficiently bondedor otherwise connected to one another to provide a substantially vaporpermeable and substantially liquid impermeable web. The backsheet 20 mayalso comprise a vapor permeable nonwoven layer which has been partiallycoated or otherwise configured to provide liquid impermeability inselected areas.

Examples of suitable materials for the backsheet 20 are also describedin U.S. Pat. No. 5,482,765 issued Jan. 9, 1996 in the name of Bradley etal. and entitled “NONWOVEN FABRIC LAMINATE WITH ENHANCED BARRIERPROPERTIES”; U.S. patent application Ser. No. 08/622,903 filed Mar. 29,1996 in the name of Odorzynski et al. and entitled “ABSORBENT ARTICLEHAVING A BREATHABILITY GRADIENT”; U.S. patent application Ser. No.08/668,418 filed Jun. 21, 1996, in the name of Good et al. and entitled“ABSORBENT ARTICLE HAVING A COMPOSITE BREATHABLE BACKSHEET”; and U.S.patent application Ser. No. 08/882,712 filed Jun. 25, 1997, in the nameof McCormack et al. and entitled “LOW GAUGE FILMS AND FILM/NONWOVENLAMINATES”, the disclosures of which are herein incorporated byreference.

In a particular embodiment, the backsheet 20 is provided by amicroporous film/nonwoven laminate material comprising a spunbondnonwoven material laminated to a microporous film. The spunbond nonwovencomprises filaments of about 1.8 denier extruded from a copolymer ofethylene with about 3.5 weight percent propylene and defines a basisweight of from about 17 to about 25 grams per square meter. The filmcomprises a cast coextruded film having calcium carbonate particlestherein and defines a basis weight of about 58 grams per square meterprior to stretching. The film is preheated, stretched and annealed toform the micropores and then laminated to the spunbond nonwoven. Theresulting microporous film/nonwoven laminate based material has a basisweight of from about 30 to about 60 grams per square meter and a watervapor transmission rate of from about 3000 to about 6000 g/sq.m/24 hr.Examples of such film/nonwoven laminate materials are described in moredetail in U.S. patent application Ser. No. 08/882,712 filed Jun. 25,1997, in the name of McCormack et al. and entitled “LOW GAUGE FILMS ANDFILM/NONWOVEN LAMINATES”, the disclosure of which has been incorporatedby reference.

The topsheet 22, as representatively illustrated in FIGS. 1 and 2,suitably presents a bodyfacing surface which is compliant, soft feeling,and nonirritating to the wearer's skin. Further, the topsheet 22 may beless hydrophilic than the absorbent body 24, to present a relatively drysurface to the wearer, and may be sufficiently porous to be liquidpermeable, permitting liquid to readily penetrate through its thickness.A suitable topsheet 22 may be manufactured from a wide selection of webmaterials, such as porous foams, reticulated foams, apertured plasticfilms, natural fibers (for example, wood or cotton fibers), syntheticfibers (for example, polyester or polypropylene fibers), or acombination of natural and synthetic fibers. The topsheet 22 is suitablyemployed to help isolate the wearer's skin from liquids held in theabsorbent body 24.

Various woven and nonwoven fabrics can be used for the topsheet 22. Forexample, the topsheet may be composed of a meltblown or spunbonded webof polyolefin fibers. The topsheet may also be a bonded-carded webcomposed of natural and/or synthetic fibers. The topsheet may becomposed of a substantially hydrophobic material, and the hydrophobicmaterial may, optionally, be treated with a surfactant or otherwiseprocessed to impart a desired level of wettability and hydrophilicity.In a particular embodiment of the present invention, the topsheet 22comprises a nonwoven, spunbond, polypropylene fabric composed of about2.8-3.2 denier fibers formed into a web having a basis weight of about22 grams per square meter and a density of about 0.06 gram per cubiccentimeter.

In a particular embodiment of the present invention, the topsheet 22 maybe surface treated with about 0.3 weight percent of a surfactant mixturewhich contains a mixture of AHCOVEL Base N-62 and GLUCOPON 220UPsurfactant in about a 3:1 ratio based on a total weight of thesurfactant mixture. The AHCOVEL Base N-62 is purchased from HodgsonTextile Chemicals Inc., a business having offices in Mount Holly, N.C.,and includes a blend of hydrogenated ethoxylated castor oil and sorbitanmonooleate in a 55:45 weight ratio. The GLUCOPON 220UP is purchased fromHenkel Corporation and includes alkyl polyglycoside. The surfactant mayalso include additional ingredients such as aloe. The surfactant may beapplied by any conventional means, such as spraying, printing, brushcoating, foam or the like. The surfactant may be applied to the entiretopsheet 22 or may be selectively applied to particular sections of thetopsheet 22, such as the medial section along the longitudinalcenterline of the diaper, to provide greater wettability of suchsections.

The topsheet 22 of the absorbent article of the present invention mayfurther include a lotion formulation on the outer bodyfacing surfacethereof. The lotion formulation may generally include an emollient, awax and, optionally, a viscosity enhancer. For example, the lotionformulation may include from about 5 to about 95 weight percent of anemollient, from about 5 to about 95 weight percent of a wax, and fromabout 1 to about 25 weight percent of a viscosity enhancer based on atotal weight of the lotion formulation. The lotion formulation mayinclude other ingredients as well.

The emollients act as lubricants to reduce the abrasiveness of thetopsheet to the skin and, upon transfer to the skin, help to maintainthe soft, smooth and pliable appearance of the skin. Suitable emollientswhich can be incorporated into the lotion formulation include oils suchas petroleum based oils, vegetable based oils, mineral oils, natural orsynthetic oils, silicone oils, lanolin and lanolin derivatives, kaolinand kaolin derivatives and the like and mixtures thereof; esters such ascetyl palmitate, stearyl palmitate, cetyl stearate, isopropyl laurate,isopropyl myristate, isopropyl palmitate and the like and mixturesthereof; glycerol esters; ethers such as eucalyptol, cetearyl glucoside,dimethyl isosorbicide polyglyceryl-3 cetyl ether, polyglyceryl-3decyltetradecanol, propylene glycol myristyl ether and the like andmixtures thereof; alkoxylated carboxylic acids; alkoxylated alcohols;fatty alcohols such as octyldodecanol, lauryl, myristyl, cetyl, stearyland behenyl alcohol and the like and mixtures thereof; and the like andmixtures thereof. For example, a particularly well suited emollient ispetrolatum. Other conventional emollients may also be added in a mannerwhich maintains the desired properties of the lotion formulations setforth herein.

To provide the improved stability and transfer to the skin of thewearer, the lotion formulation may include from about 5 to about 95weight percent, desirably from about 20 to about 75 weight percent, andmore desirably from about 40 to about 60 weight percent of theemollient. Lotion formulations which include an amount of emollientgreater than the recited amounts tend to have lower viscosities whichundesirable leads to migration of the lotion. Whereas, lotionformulations which include an amount of emollient less than the recitedamounts tend to provide less transfer to the wearer's skin.

The wax in the lotion formulations of the present invention primarilyfunctions as an immobilizing agent for the emollient and any activeingredient. In addition to immobilizing the emollient and reducing it'stendency to migrate, the wax in the lotion formulation provides atackiness to the lotion formulation which improves the transfer to theskin of the wearer. The presence of the wax also modifies the mode oftransfer in that the lotion tends to fracture or flake off instead ofactually rubbing off onto the skin of the wearer which can lead toimproved transfer to the skin. The wax may further function as anemollient, occlusive agent, moisturizer, barrier enhancer andcombinations thereof.

Suitable waxes which can be incorporated into the lotion formulationinclude animal, vegetable, mineral or silicone based waxes which may benatural or synthetic such as, for example, bayberry wax, beeswax, C30alkyl dimethicone, candelilla wax, camauba, ceresin, cetyl esters,esparto, hydrogenated cottonseed oil, hydrogenated jojoba oil,hydrogenated jojoba wax, hydrogenated microcrystalline wax, hydrogenatedrice bran wax, japan wax, jojoba butter, jojoba esters, jojoba wax,lanolin wax, microcryustalline wax, mink wax, motan acid wax, motan wax,ouricury wax, ozokerite, paraffin, PEG-6 beeswax, PEG-8 beeswax,rezowax, rice bran wax, shellac wax, spent grain wax, spermaceti wax,steryl dimethicone, synthetic beeswax, synthetic candelilla wax,synthetic carnba wax, synthetic japan wax, synthetic jojoba wax,synthetic wax, and the like and mixtures thereof. For example, aparticularly well suited wax includes about 70 weight percent ceresinwax, about 10 weight percent microcrystalline wax, about 10 weightpercent paraffin wax and about 10 weight percent cetyl esters (syntheticspermaceti wax).

To provide the improved transfer to the skin of the wearer, the lotionformulation may include from about 5 to about 95 weight percent,desirably from about 25 to about 75 weight percent, and more desirablyfrom about 40 to about 60 weight percent of the wax. Lotion formulationswhich include an amount of wax less than the recited amounts tend tohave lower viscosities which undesirable leads to migration of thelotion. Whereas, lotion formulations which include an amount of waxgreater than the recited amounts tend to provide less transfer to thewearer's skin.

A viscosity enhancer may be added to the lotion formulation to increasethe viscosity to help stabilize the formulation on the bodyfacingsurface of the topsheet 22 and thereby reduce migration and improvetransfer to the skin. Desirably, the viscosity enhancer increases theviscosity of the lotion formulation by at least about 50 percent, moredesirably at least about 100 percent, even more desirably by at leastabout 500 percent, yet even more desirably by at least about 1000percent, and even more desirably by at least about 5000 percent.Suitable viscosity enhancers which can be incorporated into the lotionformulation include polyolefin resins, lipophilic/oil thickeners,ethylene/vinyl acetate copolymers, polyethylene, silica, talc, colloidalsilicone dioxide, zinc stearate, cetyl hydroxy ethyl cellulose and othermodified celluloses and the like and mixtures thereof. For example, aparticularly well suited viscosity enhancer is an ethylene/vinyl acetatecopolymer commercially available from E. I. Dupont De Ne Mours under thetrade designation ELVAX.

To provide the improved transfer to the skin of the wearer, the lotionformulation may include from about 0.1 to about 25 weight percent,desirably from about 5 to about 20 weight percent, and more desirablyfrom about 10 to about 15 weight percent of the viscosity enhancer forreduced migration and improved transfer to the wearer's skin.

If it is desired that the lotion formulation treat the skin, it can alsoinclude an active ingredient such as a diaper rash skin protectant. Skinprotectants are a drug product which protects injured or exposed skin ormucous membrane surface from harmful or annoying stimuli. Suitableactive ingredients, in addition to those mentioned above as suitableemollients, which can be incorporated into the lotion formulationinclude, but are not limited to, alantoin and its derivatives, aluminumhydroxide gel, calamine, cocoa butter, dimethicone, cod liver oil,glycerin, kaolin and its derivatives, lanolin and its derivatives,mineral oil, shark liver oil, talc, topical starch, zinc acetate, zinccarbonate, and zinc oxide and the like, and mixtures thereof. The lotionformulation may include from about 0.10 to about 95 weight percent ofthe active ingredient depending upon the skin protectant and the amountdesired to be transferred to the skin.

In order to better enhance the benefits to the wearer, additionalingredients can be included in the lotion formulations of the presentinvention. For example, the classes of ingredients that may be used andtheir corresponding benefits include, without limitation: antifoamingagents (reduce the tendency of foaming during processing); antimicrobialactives; antifungal actives; antiseptic actives; antioxidants (productintegrity); astringents—cosmetic (induce a tightening or tinglingsensation on skin); astringent—drug (a drug product that checks oozing,discharge, or bleeding when applied to skin or mucous membrane and worksby coagulating protein); biological additives (enhance the performanceor consumer appeal of the product); colorants (impart color to theproduct); deodorants (reduce or eliminate unpleasant odor and protectagainst the formation of malodor on body surfaces); other emollients(help to maintain the soft, smooth, and pliable appearance of the skinby their ability to remain on the skin surface or in the stratum comeumto act as lubricants, to reduce flaking, and to improve the skin'sappearance); external analgesics (a topically applied drug that has atopical analgesic, anesthetic, or antipruritic effect by depressingcutaneous sensory receptors, of that has a topical counterirritanteffect by stimulating cutaneous sensory receptors); film formers (tohold active ingredients on the skin by producing a continuous film onskin upon drying); fragrances (consumer appeal),silicones/organomodified silicones (protection, tissue water resistance,lubricity, tissue softness), oils (mineral, vegetable, and animal),;natural moisturizing agents (NMF) and other skin moisturizingingredients known in the art; opacifiers (reduce the clarity ortransparent appearance of the product); powders (enhance lubricity, oiladsorption, provide skin protection, astringency, opacity, etc.); skinconditioning agents; solvents (liquids employed to dissolve componentsfound useful in the cosmetics or drugs); and surfactants (as cleansingagents, emulsifying agents, solubilizing agents, and suspending agents).

An important property of the lotion formulations of the differentaspects of the present invention is their ability to remain on thesurface of the topsheet and their resistance to migration into thearticle such that they can readily be transferred to the wearer's skin.In this regard, the articles having the lotion formulations of thepresent invention applied to there topsheet define a z-directionmigration loss of no more than about 55%, desirably no more than about50%, more desirably no more than about 45%, even more desirably no morethan about 40% and yet even more desirably no more than about 35% whensubjected to the Z-Direction Lotion Migration Test set forth below. Inarticles which have a greater z-direction migration loss, the lotionformulation undesirably migrates into the interior and along the surfaceof the topsheet and at times through the topsheet into the absorbentbody of the article which results in a lower reduction in abrasion andless transfer to the skin of the wearer.

Another important measure of the lotion formulations of the differentaspects of the present invention is their ability to resist migrationlaterally along the surface of the topsheet. In this regard, thearticles having the lotion formulations of the present invention appliedto the topsheet define a cd-direction migration loss of no more thanabout 40%, desirably no more than about 35%, more desirably no more thanabout 30%, even more desirably no more than about 25% and yet even moredesirably no more than about 20% when subjected to the CD-DirectionLotion Migration Test set forth below. In articles which have a greatercd-direction migration loss, the lotion formulation undesirably migratesalong the surface of the topsheet and at times through the topsheet intothe absorbent body of the article which results in a lower reduction inabrasion and less transfer to the skin of the wearer.

Moreover, to provide the improved stability and transfer to the skin ofthe wearer, the lotion formulation of the present invention may define amelting point of from about 30° C. to about 100° C., desirably fromabout 35° C. to about 80° C., and more desirably from about 40° C. toabout 75° C. Lotion formulations which have lower melting points exhibitmigration of the lotion during use and at elevated temperatures instorage which can undesirably result in reduced transfer to the skin.Whereas, lotion formulations which have higher melting points mayrequire that the lotion be at a temperature above the flash point of thetopsheet material which can undesirably lead to fires.

The lotion formulation of the present invention may further define amelt point viscosity of from about 50 to about 1000000 centipoise,desirably from about 50000 to about 800000 centipoise, and moredesirably from about 100000 to about 500000 centipoise for reducedmigration and improved transfer to the skin of the wearer. Lotionformulations which have lower melt point viscosities exhibit migrationof the lotion through the topsheet into the absorbent body of thearticle which can undesirably result in reduced transfer to the skin.Whereas, lotion formulations which have higher melt point viscositiesmay be so solid as to also exhibit a reduced transfer to the skin.

Further, to provide the improved stability and transfer to the skin ofthe wearer, the lotion formulation of the present invention may alsodefine a viscosity of from about 50 to about 10000 centipoise, desirablyfrom about 100 to about 500 centipoise, and more desirably from about150 to about 250 centipoise at a temperature of 60° C. Lotionformulations which have lower viscosities at 60° C. exhibit migration ofthe lotion through the topsheet into the absorbent body of the articlewhich can undesirably result in reduced transfer to the skin. Whereas,lotion formulations which have higher viscosities at 60° C. may be sosolid as to also exhibit a reduced transfer to the skin.

The penetration hardness of the lotion formulations of this inventioncan be from about 5 to about 360 millimeters, more desirably from about10 to about 200 millimeters, more desirably from about 20 to about 150millimeters, and still more desirably from about 40 to about 100millimeters. (Lotion formulations having a needle penetration hardnessgreater than 360 millimeters cannot be measured using ASTM method D1321). The hardness of the lotion formulations of this invention isimportant for two reasons. First, the softer the formulation the moremobile the formulation will be, making the formulation more likely tomigrate to the inner plies of the tissue, which is not desirable.Secondly, softer formulations tend to be more greasy/oily to the touch,which is also less desirable. In general, formulations having a needlepenetration hardness of from about 200 to about 360 millimeters feelcreamy to slightly greasy with less smoothness (depending on additives).Formulations that have needle penetration hardness values of from about5 to about 200 millimeters feel silky to creamy and very smooth(depending on additives).

The lotion formulation may be applied to the entire bodyfacing surfaceof the topsheet 22 or may be selectively applied to particular sectionsof the bodyfacing surface, such as the medial section along thelongitudinal centerline of the diaper, to provide greater lubricity ofsuch sections and to transfer such lotion to the wearer's skin.Alternatively, the bodyfacing surface of the topsheet 22 may includemultiple stripes of the lotion formulation applied thereto. For example,the bodyfacing surface of the topsheet 22 may include from 1 to 10stripes of lotion formulation extending along the longitudinal directionof the diaper 20. The stripes may extend the full length of the topsheet22 or only a portion thereof. The stripes may also define a width offrom about 0.2 to about 1 centimeters.

The lotion formulation should cover a sufficient amount of the surfacearea of the topsheet 22 to ensure adequate transfer to the skin andreduced abrasion between the topsheet 22 and the wearer's skin.Desirably, the lotion formulation is applied to at least about 5 percentand more desirably at least about 25 percent of the bodyfacing surfaceof the topsheet 22.

The lotion formulation can be applied to the topsheet at any add-onlevel which provides the desired transfer benefit. For example, thetotal add-on level of the lotion formulation can be from about 0.05 toabout 100 mg/cm², desirably from about 1 to about 50 mg/cm² and moredesirably from about 10 to about 40 mg/cm² for improved performance. Theadd-on amount will depend upon the desired effect of the lotion on theproduct attributes and the specific lotion formulation. As discussedabove, the improved stability and reduced tendency to migrate of thelotion formulations of the present invention allows a lesser amount oflotion to be applied to the topsheet 22 to achieve the same benefit whencompared with conventional lotion formulations.

The lotion formulation may be applied to the topsheet 22 in any of manywell known manners. A preferred method to uniformly apply the lotionformulation to the surface of the topsheet 22 is spraying or slotcoating, because it is the most exact process and offers maximum controlof the formulation distribution and transfer rate. However, othermethods, such as rotogravure or flexographic printing, can be used.

For example, the lotion formulation may be applied to the topsheet 22 by(a) heating the lotion formulation to a temperature above the meltingpoint of the formulation, causing the formulation to melt, (b) uniformlyapplying the melted formulation to the bodyfacing surface of thetopsheet; and (c) resolidifying the deposits of the melted formulation.Desirably, resolidification of the deposits occurs almostinstantaneously, without the need for external cooling means such aschill rolls. This can occur if the formulation is heated to atemperature only slightly above or at the melting point of theformulation. However, external means such as chill rolls, either beforeor after the application of melt, can be used if desired to accelerateresolidification.

The increased viscosity of the lotion at the process temperature and theinstantaneous resolidification tends to impede penetration of theformulation into the topsheet and absorbent body of the article andretain it on the bodyfacing surface of the topsheet 22, which isadvantageous. For example, the temperature of the melted formulation canadvantageously be less than about 10° C., more desirably less than about5° C., and still more desirably less than about 2° C. above the meltingpoint of the formulation prior to applying it to the topsheet forreduced migration. As the temperature of the melted formulationapproaches the melting point of the formulation, the viscosity of themelted formulation generally increases, which further enhances thetendency of the melted formulation to be retained on the surface.

The topsheet 22 of the absorbent article of the present invention mayfurther include a skin treatment composition on the outer bodyfacingsurface thereof for preserving and restoring the natural integrity ofthe skin. This is achieved by depositing a skin health benefit agentfrom the topsheet 22 which may control the release of the agent to thesurface of the skin. The skin health benefit agent may act as aprotectorant that is capable of maintaining the pH of the skin,inhibiting the activity of irritants to the skin, and maintaining skinhydration and lubrication. Suitable skin treatment compositions aredescribed in commonly assigned U.S. patent application Ser. No.60/141788 filed Jun. 30, 1999 in the name of Tyrrell et al., which isherein incorporated by reference.

Pancreatic digestive enzymes that are expelled by the body with feceshave been implicated to induce skin inflammation (Anderson, P. H.,Bucher, A. P., Saees, II, Lee, P. C., Davis, J. A., and Maibach, H. I.,Faecal enzymes: in vivo skin irritation. Contact Dermatitis 1994; 30,152-158). When the feces, including these enzymes, contact the skin, theskin becomes irritated. In some cases, these enzymes as well as othersfound in feces and urine, can cleave stratum comeum proteins, therebybreaking down the natural protective barrier of the skin. The skinbecomes susceptible to irritation directly by these enzymes orindirectly by other “irritants” in the feces and urine that are nowaccessible to the viable tissue. The lotion formulations and treatmentcompositions of the present invention may be designed to form a thin,tenacious, substantially continuous film over the skin to inhibit, or atleast minimize, the effect of such irritants.

The treatment composition of the present invention includes a surfactantand a skin health benefit agent. Preferably, the treatment compositionis prepared as an emulsion of the surfactant and skin health benefitagent, usually as an oil-in-water (o/w) emulsion.

Examples of emulsions include aqueous emulsions of a skin health benefitagent, e.g. zinc sulfate heptahydrate, and a surfactant such as AHCOVELBase N-62. It has been found that when emulsions containing about 75 wt.% surfactant and up to about 25 wt. % skin health benefit agent at about0.1 to 40 wt. % total solids are used, sufficient amounts of the skinhealth benefit agent transfer to the skin. Preferably, the emulsionswill contain between about 5 to 30 wt. % solids. These emulsions caneither be applied onto a substrate from a high-solids bath (up to 40 wt.%) or from dilute baths ranging from 0.1 wt. % to about 20 wt. %.Preferably, the emulsion will be diluted to about 0.5 wt. % to about15wt. %.

The surfactants useful in the treatment compositions of the presentinvention are selected to provide superior fluid handling performance,skin protection and mildness to human skin. Useful examples of suitablesurfactants include ethoxylated hydrogenated fatty oils,monosaccharides, monosaccharides derivatives, polysaccharides,polysaccharide derivatives, and combinations thereof.

Water miscible nonionic surfactants are preferred and such surfactantsare commercially available. Examples of such surfactants include AHCOVELand GLUCOPON 220UP, which is an alkylpolyglycoside having 8 to 10carbons in the alkyl chain, and may also be used as a part of thesurfactant. Other well known nonionic surfactants are the primaryaliphatic alcohol ethoxylates, secondary aliphatic alcohol ethoxylates,alkylphenol ethoxylates and ethylene-oxide-propylene oxide condensateson primary alkanols, such as PLURAFACS and PLURONICS (available fromBASF, Inc.) and condensates of ethylene oxide with sorbitan fatty acidesters such as TWEEN (also available from Uniqema). The nonionicsurfactants generally are the condensation products of an organicaliphatic or alkyl aromatic hydrophobic compound and hydrophilicethylene oxide group. Practically any hydrophobic compound having acarboxy, hydroxy, amido, or amino group with a free hydrogen attached tothe nitrogen can be condensed with ethylene oxide or with thepolyhydration product thereof, polyethylene glycol, to form a watermiscible nonionic surfactant. Other suitable surfactants includepolyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitanmonostearate, polyoxyethylene sorbitan trioleate, polyoxyethylenesorbitan tristearate, and bovine lipid extract surfactant (Survanta,Ross Laboratories), a drug used to treat Acute Respiratory DistressSyndrome and Cystic Fibrosis, and enzymes such as papain or pepsin whichcleave protein structures.

More specifically, the nonionic surfactant may include the condensationproducts of a higher alcohol (e.g., an alkanol containing about 8, 9,10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms in a straight orbranched chain configuration) condensed with about 5 to 30 moles ofethylene oxide. Examples include: lauryl or myristyl alcohol condensedwith about 16 moles of ethylene oxide (EO); tridecanol condensed withabout 6 moles of EO; myristyl alcohol condensed with about 10 moles ofEO per mole of myristyl alcohol; the condensation product of EO with acut of coconut fatty alcohol containing a mixture of fatty alcohols withalkyl chains varying from 10, 11, 12, 13 or 14 carbon atoms in lengthand wherein the condensate contains either about 6 moles of EO per moleof total alcohol or about 9 moles of EO per mole of alcohol; and tallowalcohol ethoxylates containing 6 EO to 11 EO per mole of alcohol.Condensates of 2 to 30 moles of ethylene oxide with sorbitan mono- and3C₁₀-C₂₀ alkanoic acid esters having a HLB (hydrophilic/lipophilicbalance) of about 4 to 20, preferably about 8 to 15, may also beemployed as the nonionic surfactant.

Another class of surfactant compounds include the alkyl polysaccharides.Alkyl polysaccharides are alkyl polyglycosides having the formulaSUGAR-O—R, where R is a hydrophobic group.

Suitable skin health benefit agents for use in the treatmentcompositions of the present invention include zinc compositions toreduce or prevent skin irritation and/or acute inflammatory reactions ofthe skin. Examples of such agents include zinc salt, zinc sulfatemonohydrate, and the like. Advantageously, the zinc salt will be presentin the composition as an aqueous emulsion. These agents are useful asastringents and enzyme inhibitors, and more particularly useful ininhibiting both fecal and urine proteases. Zinc can interact with thecatalytic site of the protease, in particular, the class of proteasesknown as serine proteases, to inhibit proteolytic activity. Byinhibiting the proteolytic activity, the intent is to keep the skin fromever becoming irritated, rather than treating the skin once it hasbecome irritated.

A further advantage of the skin health benefit agent of the presentinvention relates to lowering the pH. The serine proteases, e.g. trypsinand pancreatic elastase, which are present in, for example, feces andurine, are catalytically optimal at a basic pH of approximately 8.0 and8.5, respectively. The skin health benefit agent of the presentinvention has unexpectedly been found to lower the pH, therebydecreasing the catalytic efficiency of these proteases.

The skin health benefit agent is present in the treatment compositionsof the present invention in the range of from about 0.01% to about 10%by weight of the treatment composition. Preferably, the agent will bepresent in the amount of about 0.25% to about 1% by weight of thetreatment composition.

The treatment compositions of the present invention may also include aprotein that can be administered topically in a controlled manner. Onesuch protein is sericin. Sericin is one of two proteins that are part ofthe twin fibroin silk thread spun by Bombyx Mori, a domestic insect.Sericin acts as a protective envelope around the fibroin thread as it isspun, which is like spinning of fibers with soluble sizing agents tohelp form good quality fibers. The sericin can be easily separated fromsilk protein by hydrolysis. Post-spun sericin, with its uniqueproperties, is known to have high affinity to a number of proteins. Whenrefined to a high molecular weight substance it is amenable to bindingto the keratin of skin and hair, forming a resistant, moisturizing, andprotective film on the skin/hair, imparting good barrier properties.

Sericin is a silk protein obtained by controlled hydrolysis of lowmolecular weight silk having a specific gravity of at least about 1. Acommercially available silk protein is available from Croda, Inc., ofParsippany, N.J., and is sold under the trade name CROSILK LIQUID (silkamino acids), CROSILK 10,000 (hydrolyzed silk), CROSILK POWDER (powderedsilk), and CROSILKQUAT (cocodimonium hydroxypropyl silk amino acid).Another example of a commercially available silk protein is SERICIN,available from Pentapharm, LTD, a division of Kordia, by, of theNetherlands. Further details of such silk protein mixtures can be foundin U.S. Pat. No. 4,906,460, to Kim, et al., assigned to Sorenco, whichis herein incorporated by reference in its entirety.

The silk protein derivatives may be chosen from one of several potentialcompositions. Included among the silk derivatives are silk fibers andhydrolysate of silk fibers. The silk fibers may be used in the form ofpowder in preparing the emulsion or as a powder of a product obtained bywashing and treating the silk fibers with an acid. Preferably, silkfibers are used as a product obtained by hydrolysis with an acid, alkalior enzyme, as disclosed in U.S. Pat. No. 4,839,168 to Abe et al.; U.S.Pat. No. 5,009,813 to Watanube et al., and U.S. Pat. No. 5,069,898 toGoldberg, each incorporated herein by reference in its entirety.

Another silk derivative that may be employed in the composition of thepresent invention is protein obtained from degumming raw silk, asdisclosed, for example, in U.S. Pat. No. 4,839,165 to Hoppe et al.,incorporated herein by reference in its entirety. The principal proteinobtained from the raw silk is sericin, which has an empirical formula ofC₁₅H₂₅O₃N₅ and a molecular weight of about 323.5.

A preferred silk derivative is a mixture of two or more individual aminoacids, which naturally occur in silk. The principal silk amino acids areglycine, alanine, serine and tyrosine.

Another example of a silk derivative for use in the emulsion compositionof the present invention is a fine powder of silk fibroin in nonfibrousor particulate form, as disclosed in U.S. Pat. No. 4,233,212 to Otoi etal., incorporated herein by reference in its entirety. The fine powderis produced by dissolving a degummed silk material in at least onesolvent selected from, for example, an aqueous cupriethylene diaminesolution, an aqueous ammonia solution of cupric hydroxide, an aqueousalkaline solution of cupric hydroxide and glycerol, an aqueous lithiumbromide solution, an aqueous solution of the chloride, nitrate orthiocyanate of calcium, magnesium or zinc and an aqueous sodiumthiocyanate solution. The resulting fibroin solution is then dialyzed.The dialyzed aqueous silk fibroin solution, having a silk fibroinconcentration of from about 3 to 20% by weight, is subjected to at leastone treatment for coagulating and precipitating the silk fibroin, suchas, for example, by the addition of a coagulating salt, by aeration, bycoagulation at the isoelectric point, by exposure to ultrasonic waves,by agitation at high shear rate and the like. The resulting product is asilk fibroin gel, which may be incorporated directly into a treatmentcomposition or the same may be dehydrated and dried into a powder andthen dissolved in the treatment composition.

The silk material used to form the silk fibroin includes cocoons, rawsilk, waste cocoons, raw silk waste, silk fabric waste and the like. Thesilk material is degummed or freed from sericin by a conventionalprocedure such as, for example, by washing in warm water containing asurfactant-active agent or an enzyme, and then dried. The degummedmaterial is dissolved in the solvent and preheated to a temperature offrom about 60 to 95° C., preferably of from about 70 to 85° C. Furtherdetails of the process of obtaining the silk fibroin are discussed inpreviously referenced U.S. Pat. No. 4,233,212.

In addition to the silk protein in the treatment compositions of thepresent invention, an additional protein may be present in the amount ofabout 0.1 to about 4.0% by weight. This additional protein may beselected from the group consisting of hydrolyzed animal collagen proteinobtained by an enzymatic hydrolysis, lexeine protein, vegetal proteinand hydrolyzed wheat protein and mixtures thereof.

The treatment compositions of the present invention can be in the formof an oil-in-water (o/w) emulsion or after dilution with water, with theessential ingredients being water, surfactant, and/or co-surfactant.

Because the composition as prepared is an aqueous liquid formulation andsince no particular mixing is required to form the o/w emulsion, thecomposition is easily prepared simply by combining all the ingredientsin a suitable vessel or container. The order of mixing the ingredientsis not particularly important and generally the various ingredients canbe added sequentially or all at once or in the form of aqueous emulsionsof each or all of the primary surfactants and co-surfactants can beseparately prepared and combined with each other. It is important tonote that emulsions of, for instance, organic acid emulsions would notbe acceptable for use in the present invention, since such emulsionswould be a strong skin irritant and counterproductive to the intendeduse of the present invention. The protein, when present, can be added asan aqueous emulsion thereof or can be added directly. It is notnecessary to use elevated temperatures in the formation step and roomtemperature is sufficient. However, higher temperatures of up to about180° F. (82.2° C.), preferably 110 to 140° F. (43.3 to 60° C.), can alsobe used.

For administration to the skin of a human or other mammal, the treatmentcompositions will often be sterilized or formulated to contain one ormore preservatives for incorporation into pharmaceutical, cosmetic orveterinary formulations. These treatment compositions can be sterilizedby conventional, well-known sterilization techniques, e.g., boiling orpasteurization, without substantially adversely affecting the biologicalactivity of the composition. The compositions may containpharmaceutically acceptable auxiliary substances as required toapproximate physiological conditions and as necessary to preparecompositions for convenient administration, such as those describedabove in connection with the description of the lotion formulation, suchas pH adjusting and buffering agents, preservatives, and deliveryvehicles. Actual methods for preparing pharmaceutically administrablecompounds will be known or apparent to those skilled in the art and aredescribed in detail in, for example, Remington's Pharmaceutical Science,supra.

Perfumes, dyes and pigments can also be incorporated into the treatmentcompositions of the invention. For semi-solid compositions, as would beappropriate for pastes and creams intended for topical administration,the peptone-copper complexes can be provided separately or may becompounded with conventional nontoxic carriers such as, for example,aloe vera gel, squalene, glycerol stearate, polyethylene glycol, cetylalcohol, stearic acid, and propylene glycol, among others. Suchcompositions may contain about 5-100% active ingredients, morepreferably about 5-25%.

The treatment compositions may be administered to a wearer of thearticle with uncompromised skin or in situations where a subject isalready suffering from damaged skin (e.g., peeling) due to ultravioletor other irradiation or oxidative skin damage. The treatmentcompositions incorporated onto the topsheet 22 such that they areadministered in an amount sufficient to allow inhibition of furtherdamage by topically administered irritating substances or other unknownirritating substances and are more effective than if the host were nottreated. Amounts adequate to accomplish these effects are defined as a“therapeutically effective dose” and will vary according to theapplication.

In prophylactic and cosmetic applications, the treatment compositionsare employed for protecting the skin from damage. Thus, the skin healthbenefit agents and/or silk proteins are administered to a host underconditions which protect the integrity of the skin, maintainsphysiological pH, skin hydration and lubrication. In these uses, theprecise amounts again depend on the amount of protection desired and theextent and conditions under which the skin is exposed to potentiallydamaging conditions, such as those caused by fecal and urine proteases,or other irritating substances. They can generally range from about 0.1mg to about 10 mg per day per square centimeter of skin. Single ormultiple administrations of the compositions can be carried out daily orover a prolonged period of time.

The silk proteins of the invention may be administered to the skin inrelatively large amounts without serious side effects, althoughindiscriminate use may produce irritation of the skin. In instanceswhere the compositions are administered prophylactically to inhibitoxidative or biochemical damage to the skin or to those suffering fromonly mild skin damage, irritation or inflammation of the skin, the dosemay be adjusted to lower maintenance levels.

The treatment compositions providing skin protection and enhanced repairof the present invention, including pharmaceutical compositions, may beincorporated onto the topsheet 22 of the articles of the presentinvention and be administered alone or as combination or adjunct therapyor prophylaxis. For example, the treatment compositions can be used incombination with other skin protective factors or those found to improveother aspects of protection or healing such as the lotion formulationsdescribed above. In this manner a synergistic effect may be attainedthat yields a clinical efficacy greater than that realized with anysingle factor.

Further, while the treatment compositions described herein stimulate aspectrum of skin protective processes, skin can differ considerably inits properties, leading one to utilize a combination of a compositiondescribed herein and another compound or factor.

Factors with reported healing properties which can be included with thesilk protein compositions for use in protective/healing formulations andmethods of the present invention include, for example, epidermal growthfactor, fibroblast growth factor, nerve growth factor, transforminggrowth factors, angiogenic growth factors, heparin, fibronectin, fibrin,platelet-derived growth factor, enzymatic superoxide dismutase, extractsof blood or factors from the blood, and other similar factors.

The treatment compositions may be added to the topsheet 22 byconventional means such as spraying, coating, dipping and the likealthough the use of high solids spray is advantageous in cases wheredrying and/or compression is desired to be minimized. The amount of thetreatment composition used will depend on the particular end use as wellas factors such as basis weight and porosity of the substrate.

A unique and surprising aspect of the treatment compositions of thepresent invention includes their ability to be transferred from thetopsheet to the skin. It has been found that when a liquid is introducedto the topsheet, the treatment composition will dissolve in the liquid,and then liquid-mediated transfer of the treatment composition to theskin occurs. In other words, the treatment composition including theskin health benefit agent dissolves off of the substrate into theliquid, which then deposits the thin, tenacious and substantiallycontinuous film of the skin health benefit agent onto the skin. Urine isan example of a liquid that can transfer the treatment composition fromthe topsheet 22 to the skin. As another example, the liquid generated bythe body after abrasion or injury to the skin, might provide sufficientliquid-mediated transfer of the treatment composition from the topsheet.In general, when wetness increases, the treatment composition willtransfer from the topsheet to the skin to form a protective barrier.

The absorbent body 24 of the diaper 10, as representatively illustratedin FIGS. 1 and 2, may suitably comprise a matrix of hydrophilic fibers,such as a web of cellulosic fluff, mixed with particles of ahigh-absorbency material commonly known as superabsorbent material. In aparticular embodiment, the absorbent body 24 comprises a matrix ofcellulosic fluff, such as wood pulp fluff, and superabsorbenthydrogel-forming particles. The wood pulp fluff may be exchanged withsynthetic, polymeric, meltblown fibers or with a combination ofmeltblown fibers and natural fibers. The superabsorbent particles may besubstantially homogeneously mixed with the hydrophilic fibers or may benonuniformly mixed. Alternatively, the absorbent body 24 may comprise alaminate of fibrous webs and superabsorbent material or other suitablemeans of maintaining a superabsorbent material in a localized area.

The absorbent body 24 may have any of a number of shapes. For example,the absorbent core may be rectangular, I-shaped, or T-shaped. It isgenerally preferred that the absorbent body 24 be narrower in theintermediate section than in the front or rear waist sections of thediaper 10. The absorbent body 24 may be provided by a single layer or,in the alternative, may be provided by multiple layers, all of whichneed not extend the entire length and width of the absorbent body 24. Ina particular aspect of the invention, the absorbent body 24 can begenerally T-shaped with the laterally extending cross-bar of the “T”generally corresponding to the front waist section 12 of the absorbentarticle for improved performance, especially for male infants. In theillustrated embodiments, for example, the absorbent body 24 across thefront waist section 12 of the article has a cross-directional width ofabout 18 centimeters, the narrowest portion of the intermediate section16 has a width of about 7.5 centimeters and in the rear waist section 14has a width of about 11.4 centimeters.

The size and the absorbent capacity of absorbent body 24 should becompatible with the size of the intended wearer and the liquid loadingimparted by the intended use of the absorbent article. Further, the sizeand the absorbent capacity of the absorbent body 24 can be varied toaccommodate wearers ranging from infants through adults. In addition, ithas been found that with the present invention, the densities and/orbasis weights of the absorbent body 24 can be varied. In a particularaspect of the invention, the absorbent body 24 has an absorbent capacityof at least about 300 grams of synthetic urine.

In embodiments wherein the absorbent body 24 includes the combination ofhydrophilic fibers and high-absorbency particles, the hydrophilic fibersand high-absorbency particles can form an average basis weight for theabsorbent body 24 which is within the range of about 400-900 grams persquare meter. In certain aspects of the invention, the average compositebasis weight of such an absorbent body 24 is within the range of about500-800 grams per square meter, and preferably is within the range ofabout 550-750 grams per square meter to provide the desired performance.

To provide the desired thinness dimension to the various configurationsof the absorbent article of the invention, the absorbent body 24 can beconfigured with a bulk thickness which is not more than about 0.6centimeters. Preferably, the bulk thickness is not more than about 0.53centimeters, and more preferably is not more than about 0.5 centimetersto provide improved benefits. The bulk thickness is determined under arestraining pressure of 0.2 psi (1.38 kPa).

The high-absorbency material can be selected from natural, synthetic,and modified natural polymers and materials. The high-absorbencymaterials can be inorganic materials, such as silica gels, or organiccompounds, such as crosslinked polymers. The term “crosslinked” refersto any means for effectively rendering normally water-soluble materialssubstantially water insoluble but swellable. Such means can include, forexample, physical entanglement, crystalline domains, covalent bonds,ionic complexes and associations, hydrophilic associations such ashydrogen bonding, and hydrophobic associations or Van der Waals forces.

Examples of synthetic, polymeric, high-absorbency materials include thealkali metal and ammonium salts of poly(acrylic acid) andpoly(methacrylic acid), poly(acrylamides), poly(vinyl ethers), maleicanhydride copolymers with vinyl ethers and alpha-olefins, poly(vinylpyrrolidone), poly(vinyl morpholinone), poly(vinyl alcohol), andmixtures and copolymers thereof. Further polymers suitable for use inthe absorbent core include natural and modified natural polymers, suchas hydrolyzed acrylonitrile-grafted starch, acrylic acid grafted starch,methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, andthe natural gums, such as alginates, xanthum gum, locust bean gum, andthe like. Mixtures of natural and wholly or partially syntheticabsorbent polymers can also be useful in the present invention.

The high absorbency material may be in any of a wide variety ofgeometric forms. As a general rule, it is preferred that the highabsorbency material be in the form of discrete particles. However, thehigh absorbency material may also be in the form of fibers, flakes,rods, spheres, needles, or the like. In general, the high absorbencymaterial is present in the absorbent body in an amount of from about 5to about 90 weight percent, desirably in an amount of at least about 30weight percent, and even more desirably in an amount of at least about50 weight percent based on a total weight of the absorbent body 24. Forexample, in a particular embodiment, the absorbent body 24 may comprisea laminate which includes at least about 50 weight percent and desirablyat least about 70 weight percent of high-absorbency material overwrappedby a fibrous web or other suitable means of maintaining thehigh-absorbency material in a localized area.

An example of high-absorbency material suitable for use in the presentinvention is SANWET IM 3900 polymer available from Hoechst Celanese, abusiness having offices in Portsmouth, Va. Other suitablesuperabsorbents may include FAVOR SXM 880 polymer obtained fromStockhausen, a business having offices in Greensboro, N.C.

Optionally, a substantially hydrophilic tissue wrapsheet (notillustrated) may be employed to help maintain the integrity of thestructure of the absorbent body 24. The tissue wrapsheet is typicallyplaced about the absorbent body over at least the two major facingsurfaces thereof and composed of an absorbent cellulosic material, suchas creped wadding or a high wet-strength tissue. In one aspect of theinvention, the tissue wrap can be configured to provide a wicking layerwhich helps to rapidly distribute liquid over the mass of absorbentfibers comprising the absorbent body.

The absorbent body 24 of the different aspects of the present inventionfurther includes a plurality of zones of high air permeability whichallow air and vapors to readily pass through the absorbent body 24 andthrough the vapor permeable backsheet 20 out of the diaper 10 intoambient air. For example, as representatively illustrated in FIGS. 1 and2, the absorbent body 24 may include a plurality of air passageways 40which provide the absorbent body 24 with the zones or regions of highair permeability 42. In the illustrated embodiment, the portions of theabsorbent body 24 adjacent the air passageways 40 provide zones orregions of high absorption 44. The zones of high air permeability 42 aredesigned to provide the maximum air exchange from the absorbent body 24while the zones of high absorption 44 are designed to receive and holdthe majority of the body exudates. The absorbent body 24 may define anynumber of zones of high air permeability 42 which provides the improvedair exchange. Desirably, the absorbent body 24 defines at least 3 andmore desirably at least 5 different zones of high air permeability 42for improved performance.

The zones of high air permeability 42, such as the air passageways 40 asrepresentatively illustrated in FIGS. 1 and 2, are configured to enhancethe breathability of the article to reduce the hydration of the wearer'sskin during use without allowing excessive condensation of vapor, suchas urine, on the garment facing surface of the backsheet 20. Suchcondensation of vapor on the outer surface of the diaper 10 canundesirably dampen the wearer's clothes. The zones of high airpermeability 42 are generally located in the area of the diaper overwhich air and vapor can transfer from the topsheet 22, through theabsorbent body 24 and any other intervening layer or layers of material,and out the vapor permeable backsheet 20. For example, the zones of highair permeability 42 may be located throughout the entire absorbent body24 or may be selectively located in those regions of the absorbent body24 which provide the maximum air exchange, such as the intermediatesection 16 of the diaper 20. In a particular embodiment, the zones ofhigh air permeability 42 are located in the front and intermediatesections 12 and 16, respectively, of the diaper 10 for improved airexchange.

The zones of high absorption 44, on the other hand, are not designed totransfer a high level of air and vapor from the interior of the diaper.Thus, the air exchange from the topsheet 22 of the diaper 10 to thebacksheet 20 of the diaper and into the ambient atmosphere (exterior ofthe diaper) occurs generally through the absorbent body 24 in the zonesof high air permeability 42. Some air exchange through the absorbentbody 24 can also occur in the zones of high absorption 44 to a limiteddegree.

The zones of high air permeability may have any desired configurationincluding rectangular, circular, hourglass, oval, and the like, and mayalso include selected longitudinal or lateral strips or multiple regionswhich may be intermittently located. For example, in FIGS. 1 and 2, thezones of high air permeability 42 are provided by a plurality of airpassageways 40 or apertures through the absorbent body 24 which have agenerally circular configuration. In such a configuration, the zones ofhigh absorption 44 comprise the non-apertured portions of the absorbentbody 24 between the air passageways 40.

The zones of high air permeability 42 may have any desired dimensionswhich effectively provide improved air exchange while preventingexcessive condensation of vapor from the absorbent body 24 through andonto the garment facing surface of the backsheet 20. Desirably, thezones of high air permeability 42 may define a total area of from about5 to about 75 percent, more desirably at least about 10 percent, evenmore desirably from about 10 to about 70 percent, and still moredesirably from about 10 to about 60 percent of the total surface area ofthe absorbent body 24 of the diaper 10. For example, in a diaperintended for use on a medium sized infant, the zones of high airpermeability 42 may define a total area of from about 6 to about 90square centimeters.

When the total area of the zones of high air permeability 42 is greaterthan the above amounts, the diaper 10 may exhibit an undesirable amountof condensation of vapor on the exposed, garment facing surface of thebacksheet 20 undesirably resulting in a clammy feeling on the outersurface of the diaper. Whereas, when the total area of the zones of highair permeability 42 is less than the above amounts, the diaper 10 mayexhibit a low level of air exchange resulting in high levels of skinhydration which can undesirably lead to skin irritation and rash.

The zones of high air permeability 42 of the absorbent body 24 of thediaper 10, as representatively illustrated in FIGS. 1 and 2, areconstructed to be substantially permeable to at least air and preferablypermeable to water vapor. For example, the zones of high airpermeability 42 of the absorbent body 24 define a Frazier Porosity valuewhich is at least about 10 percent, more desirably at least about 20percent and even more desirably at least about 50 percent greater thanthe Frazier Porosity value of the zones of high absorption 44 of theabsorbent body 24. As used herein, the term “Frazier Porosity” refers tothe value determined according to the Frazier Porosity Test set forthbelow. When the zones of high air permeability exhibit Frazier Porosityvalues less than those indicated above, the diaper 10 may exhibit a lowlevel of air exchange resulting in high levels of skin hydration whichcan undesirably lead to skin irritation and rash.

The zones of high air permeability may be provided in a variety of ways.The zones of high air permeability 42 may be integral portions of theabsorbent body 24 of the absorbent article or may be provided byapertures, holes or open spaces in the absorbent body 24. For example,portions of the absorbent body 24 may be discontinuous or removed toprovide the zones 42. Alternatively, the zones of high air permeability42 may be provided by portions of the absorbent body 24 which areconstructed to absorb less fluid exudates thereby resulting in improvedair flow through such portions in use. For example, portions of theabsorbent body 24 may be void of or contain substantially lesshigh-absorbency material than other portions of the absorbent body 24 toprovide such improved air flow. Portions of the absorbent body 24 mayotherwise be treated or coated with a solution which renders themhydrophobic to provide the zones of high air permeability 42 in selectedareas. In other alternative configurations, the zones of high airpermeability 42 may be provided by creating voids or holes in theabsorbent body 24 and placing other materials having a higher airpermeability than the absorbent body 24, such as those materialsdescribed below as being suitable for the surge management layer 34 , inthe holes or voids.

Examples of several configurations of the absorbent body 24 according todifferent aspects of the present invention are representativelyillustrated in FIGS. 1-6. For example, in FIGS. 1 and 2, the zones ofhigh air permeability 42 in the absorbent body 24 are provided by aplurality of air passageways 40 or apertures through the absorbent body24. In the illustrated embodiment, the air passageways 40 areintermittently positioned along the entire length and width of theabsorbent body 24. The illustrated air passageways 40 are circular anddefine a diameter of about 1.27 centimeters and a total open area ofabout 12 percent of a total surface area of the absorbent body 24.

In FIGS. 3 and 4, the absorbent body 24 is in the form of discretesegments 46 which are spaced apart along the longitudinal direction 36of the diaper 10. In such a configuration, the zones of high airpermeability 42 are provided by the spaces between the discrete segments46 of the absorbent body 24. The absorbent body 24 may include anynumber of segments 46 having a variety of shapes and sizes. For example,in the illustrated embodiment, the absorbent body 24 includes fourdifferent segments 46 spaced apart in the longitudinal direction 36 ofthe diaper 10. The illustrated segments 46 are generally rectangular inshape and define a width which is less than a width of the absorbentbody 24 which, in the illustrated embodiment, is defined by the width ofthe surge management layer 34 and the ventilation layer 32 as describedbelow. Alternatively, the segments 46 may define a width which issubstantially equal to a width of the absorbent body 24. To assist inmaintaining the segments 46 in the spaced apart relationship, thesegments 46 can be contained between two sheets of material such aswrapsheet (not shown) or the surge management layer 34 and theventilation layer 32. In the illustrated embodiment, the segments 46include a laminate of high-absorbency material between two sheets orlayers of material and the zones of high air permeability 42 provided bythe spaces between the segments 46 define an open area of about 40percent of a total surface are of the absorbent body 24.

In FIGS. 5 and 6, the zones of high air permeability 42 in the absorbentbody 24 are provided by a plurality of air passageways 40 or aperturesthrough the absorbent body 24 similar to the embodiment illustrated inFIGS. 1 and 2. However, in the embodiment illustrated in FIGS. 5 and 6,the air passageways 40 are located in the absorbent body 24 in the frontwaist section 12 and the intermediate section 16 of the diaper 10 andnot in the rear waist section 14. Moreover, in the embodimentillustrated in FIGS. 5 and 6, the absorbent body 24 includes an upperlayer 48 and a lower layer 50 with the upper layer 48 extending onlyalong a portion of the length of the absorbent body 24. In such aconfiguration, the majority of the absorbent body 24 can be located inthe front waist and intermediate sections 12 and 16 of the diaper 10 forimproved absorption and reduced cost. The illustrated air passageways 40are circular and define a diameter of about 1.27 centimeters and a totalopen area of about 12 percent of a total surface area of the absorbentbody 24.

Due to the thinness of absorbent body 24 and the high absorbencymaterial within the absorbent body 24, the liquid uptake rates of theabsorbent body 24, by itself, may be too low, or may not be adequatelysustained over multiple insults of liquid into the absorbent body 24. Toimprove the overall liquid uptake and air exchange, the diaper of thedifferent aspects of the present invention may further include a porous,liquid-permeable layer of surge management material 34, asrepresentatively illustrated in FIGS. 1 and 2. The surge managementlayer 34 is typically less hydrophilic than the absorbent body 24, andhas an operable level of density and basis weight to quickly collect andtemporarily hold liquid surges, to transport the liquid from its initialentrance point and to substantially completely release the liquid toother parts of the absorbent body 24. This configuration can helpprevent the liquid from pooling and collecting on the portion of theabsorbent garment positioned against the wearer's skin, thereby reducingthe feeling of wetness by the wearer. The structure of the surgemanagement layer 34 also generally enhances the air exchange within thediaper 10.

Various woven and nonwoven fabrics can be used to construct the surgemanagement layer 34. For example, the surge management layer 34 may be alayer composed of a meltblown or spunbonded web of synthetic fibers,such as polyolefin fibers. The surge management layer 34 may also be abonded-carded-web or an airlaid web composed of natural and syntheticfibers. The bonded-carded-web may, for example, be a thermally bondedweb which is bonded using low melt binder fibers, powder or adhesive.The webs can optionally include a mixture of different fibers. The surgemanagement layer 34 may be composed of a substantially hydrophobicmaterial, and the hydrophobic material may optionally be treated with asurfactant or otherwise processed to impart a desired level ofwettability and hydrophilicity. In a particular embodiment, the surgemanagement layer 34 includes a hydrophobic, nonwoven material having abasis weight of from about 30 to about 120 grams per square meter.

For example, in a particular embodiment, the surge management layer 34may comprise a bonded-carded-web, nonwoven fabric which includesbicomponent fibers and which defines an overall basis weight of about 83grams per square meter. The surge management layer 34 in such aconfiguration can be a homogeneous blend composed of about 60 weightpercent polyethylene/polyester (PE/PET), sheath-core bicomponent fiberswhich have a fiber denier of about 3 d and about 40 weight percentsingle component polyester fibers which have a fiber denier of about 6 dand which have fiber lengths of from about 3.8 to about 5.08centimeters.

In the illustrated embodiments, the surge management layer 34 isarranged in a direct, contacting liquid communication with the absorbentbody 24. The surge management layer 34 may be operably connected to thetopsheet 22 with a conventional pattern of adhesive, such as a swirladhesive pattern. In addition, the surge management layer 34 may beoperably connected to the absorbent body 24 with a conventional patternof adhesive. The amount of adhesive add-on should be sufficient toprovide the desired levels of bonding, but should be low enough to avoidexcessively restricting the movement of liquid from the topsheet 22,through the surge management layer 34 and into the absorbent body 24.

The absorbent body 24 is positioned in liquid communication with surgemanagement layer 34 to receive liquids released from the surgemanagement layer, and to hold and store the liquid. In the shownembodiments, the surge management layer 34 comprises a separate layerwhich is positioned over another, separate layer comprising theabsorbent body 24, thereby forming a dual-layer arrangement. The surgemanagement layer 34 serves to quickly collect and temporarily holddischarged liquids, to transport such liquids from the point of initialcontact and spread the liquid to other parts of the surge managementlayer 34, and then to substantially completely release such liquids intothe layer or layers comprising the absorbent body 24.

The surge management layer 34 can be of any desired shape. Suitableshapes include for example, circular, rectangular, triangular,trapezoidal, oblong, dog-boned, hourglass-shaped, or oval. In certainembodiments, for example, the surge management layer can be generallyrectangular-shaped. In the illustrated embodiments, the surge managementlayer 34 is coextensive with the absorbent body 24. Alternatively, thesurge management layer 34 may extend over only a part of the absorbentbody 24. Where the surge management layer 34 extends only partiallyalong the length of the absorbent body 24, the surge management layer 34may be selectively positioned anywhere along the absorbent body 24. Forexample, the surge management layer 34 may function more efficientlywhen it is offset toward the front waist section 12 of the garment. Thesurge management layer 34 may also be approximately centered about thelongitudinal center line of the absorbent body 24.

Additional materials suitable for the surge management layer 34 are setforth in U.S. Pat. No. 5,486,166 issued Jan. 23, 1996 in the name of C.Ellis et al. and entitled “FIBROUS NONWOVEN WEB SURGE LAYER FOR PERSONALCARE ABSORBENT ARTICLES AND THE LIKE”; U.S. Pat. No. 5,490,846 issuedFeb. 13, 1996 in the name of Ellis et al. and entitled “IMPROVED SURGEMANAGEMENT FIBROUS NONWOVEN WEB FOR PERSONAL CARE ABSORBENT ARTICLES ANDTHE LIKE”; and U.S. Pat. No. 5,364,382 issued Nov. 15, 1994 in the nameof Latimer et al. and entitled “ABSORBENT STRUCTURE HAVING IMPROVEDFLUID SURGE MANAGEMENT AND PRODUCT INCORPORATING SAME”, the disclosuresof which are hereby incorporated by reference.

As representatively illustrated in FIGS. 1 and 2, the diaper 10 may alsoinclude a ventilation layer 32 located between the backsheet 20 and theabsorbent body 24. The ventilation layer 32 serves to facilitate themovement of air within and through the diaper 10 and prevent thebacksheet 20 from being in surface to surface contact with at least aportion of the absorbent body 24. Specifically, the ventilation layer 32serves as a conduit through which air and water vapor can move from theabsorbent body 24 through the vapor permeable backsheet 20.

The ventilation layer 32 may be formed from materials described above asbeing suitable for the surge management layer 34 such as nonwoven,(e.g., spunbond, meltblown or carded), woven, or knitted fibrous webscomposed of natural fibers and/or synthetic polymeric fibers. Suitablefibers include, for example, acrylic fibers, polyolefin fibers,polyester fibers, or blends thereof. The ventilation layer 32 may alsobe formed from a porous foam material such as an open-celled polyolefinfoam, a reticulated polyurethane foam, and the like. The ventilationlayer 32 may include a single layer of material or a composite of two ormore layers of material. In a particular embodiment, the ventilationlayer 32 includes a hydrophobic, nonwoven material having a thickness ofat least about 0.10 centimeters determined under a restraining pressureof 0.05 psi (0.34 kPa) and a basis weight of from about 20 to about 120grams per square meter. For example, the ventilation layer 32 maycomprise a bonded-carded-web, nonwoven fabric which includes bicomponentfibers and which defines an overall basis weight of about 83 grams persquare meter. The ventilation layer 32 in such a configuration can be ahomogeneous blend composed of about 60 weight percentpolyethylene/polyester (PE/PET), sheath-core bicomponent fibers whichhave a fiber denier of about 3 d and about 40 weight percent singlecomponent polyester fibers which have a fiber denier of about 6 d andwhich have fiber lengths of from about 3.8 to about 5.08 centimeters.

The ventilation layer 32 can be of any desired shape. Suitable shapesinclude for example, circular, rectangular, triangular, trapezoidal,oblong, dog-boned, hourglass-shaped, or oval. The ventilation layer 32may extend beyond, completely over or partially over the absorbent body24. For example, the ventilation layer 32 may suitably be located overthe intermediate section 16 of the diaper 10 and be substantiallycentered side-to-side with respect to the longitudinal centerline 36 ofthe diaper 10. It is generally desired that the entire absorbent body 24be overlaid with the ventilation layer 32 to prevent substantially allsurface to surface contact between the backsheet 20 and the absorbentbody 24. In the illustrated embodiments, the ventilation layer 32 iscoextensive with the absorbent body 24. This allows for the maximumdegree of air exchange with minimal dampness on the garment facingsurface of the backsheet 20.

In the illustrated embodiments, the ventilation layer 32 is arranged ina direct, contacting liquid communication with the absorbent body 24.The ventilation layer 32 may be operably connected to the backsheet 20with a conventional pattern of adhesive, such as a swirl adhesivepattern. In addition, the ventilation layer 32 may be operably connectedto the absorbent body 24 with a conventional pattern of adhesive. Theamount of adhesive add-on should be sufficient to provide the desiredlevels of bonding, but should be low enough to avoid excessivelyrestricting the movement of air and vapor from the absorbent body 24 andthrough the backsheet 20.

The ventilation layer 32 may further serve to quickly collect andtemporarily hold discharged liquids, which pass through the absorbentbody 24 and, in particular, through the zones of high air permeability42 within the absorbent body 24. The ventilation layer 32 may thentransport such liquids from the point of initial contact and spread theliquid to other parts of the ventilation layer 32, and thensubstantially completely release such liquids into the layer or layerscomprising the absorbent body 24.

The different article embodiments of the present invention, asrepresentatively illustrated in FIGS. 1-6, advantageously provideimproved absorbent articles which exhibit substantially reduced levelsof hydration of the wearer's skin when in use compared to conventionalabsorbent articles. In particular, the reduced levels of skin hydrationpromote drier, more comfortable skin and render the skin lesssusceptible to the viability of microorganisms. Thus, wearer's ofabsorbent articles made according to the present invention have reducedskin hydration which can lead to a reduction in the incidence of skinirritation and rash.

Moreover, the combination of the highly breathable articles of thepresent invention with the lotion formulations and/or treatmentcompositions of the present invention can provide a synergisticreduction in the incidence of skin irritation and rash. In particular,the lotion formulations and treatment compositions can provide a skinbarrier and anti-inflammatory function. Thus, the absorbent articlesmade according to the present invention can maintain or improve thehealth of the wearer's skin.

TEST PROCEDURES

Hydrostatic Pressure Test

The Hydrostatic Pressure Test is a measure of the liquid barrierproperties of a material. In general, the Hydrostatic Pressure Testdetermines the height of water (in centimeters) in a column which thematerial will support before a predetermined amount of water passesthrough. A material with a higher hydrohead value indicates it is agreater barrier to liquid penetraton than a material having a lowerhydrohead value. The Hydrostatic Pressure Test is performed according toMethod 5514—Federal Test Methods Standard No. 191A.

Frazier Porosity Test

The Frazier Porosity values referred to in the present specification canbe determined employing a Frazier Air Permeability Tester (FrazierPrecision Instrument Co., Gaithersburg, Md.) and Method 5450, FederalTest Methods Standard No. 191A. For the purposes of the presentinvention, the test is conducted with a sample which measures 8 inches×8inches.

Water Vapor Transmission Test

A suitable technique for determining the WVTR (water vapor transmissionrate) value of a material is as follows. For the purposes of the presentinvention, 3-inch diameter (76 millimeter) circular samples are cut fromthe test material and from a control material, Celguarde® 2500 (HoechstCelanese Corporation). Two or three samples are prepared for eachmaterial. Test cups used for testing are cast aluminum, flanged, 2inches deep and come with a mechanical seal and neoprene gasket. Thecups are distributed by Thwing-Albert Instrument Company, Philadelphia,Pa., under the designation Vapometer cup #681. One hundred millilitersof distilled water are poured into each Vapometer cup, and each of theindividual samples of the test materials and control material are placedacross the open top area of an individual cup. Screw-on flanges aretightened to form a seal along the edges of the cups leaving theassociated test material or control material exposed to the ambientatmosphere over a 62 millimeter diameter circular area (an open, exposedarea of about 30 cm²). The cups are then weighed, placed on a tray, andset in a forced air oven set at 100° F. (38° C.). The oven is a constanttemperature oven with external air circulating through it to preventwater vapor accumulation inside. A suitable forced air oven is, forexample, a Blue M Power-O-Matic 60 oven distributed by Blue M ElectricCo. of Blue Island, Ill. After 24 hours, the cups are removed from theoven and weighed. The preliminary, test WVTR value is calculated asfollows:${{Test}\quad {WVTR}} = {\frac{\left\lbrack {\left( {{grams}\quad {weight}\quad {loss}\quad {over}\quad 24\quad {hours}} \right) \times 7571} \right\rbrack}{24}\left( {{{g/m^{2}}/24}\quad {hours}} \right)}$

The relative humidity within the oven is not specifically controlled.Under predetermined set conditions of 100° F. and ambient relativehumidity, the WVTR for Celguard 2500 has been determined to be 5000g/m²/24 hours. Accordingly, Celguard 2500 is run as a control samplewith each test. Celguard 2500 is a 0.0025 cm thick film composed of amicroporous polypropylene.

Skin Hydration Test

Skin hydration values are determined by measuring total evaporativewater loss (EL) and can be determined by employing the following testprocedure.

The test is conducted on partially toilet trained infants who have nolotions or ointments on the skin and have not been bathed within 2 hoursprior to the test. Each infant tests one diaper during each testsession. The test diapers include a test code and a control code. Thetest diapers (test code and control code) are randomized.

Each test diaper is weighed before and after use to verify the volume ofliquid added into the diaper. A felt tip pen is employed to mark an “X”at the target zone inside the diaper, with the “X” positioned 6.5 inchesbelow the top front edge of the diaper and centered side-to-side. The ELmeasurements are taken with an evaporimeter, such as an Evaporimeter EP1instrument distributed by Servomed AB, Stockholm, Sweden. Each testmeasurement is taken over a period of two minutes with EWL values takenonce per second (a total of 120 EWL values). The digital output from theEvaporimeter EP1 instrument gives the rate of evaporative water loss(EWL) in g/m²/hr. Skin hydration values (SHV) are in units of totalamount of water loss per unit area measured during the two-minutesampling period and are calculated as follows.${{SHV}\left( {{g/m^{2}}/{hour}} \right)} = \frac{\sum\limits_{n = 1}^{120}({EWL})_{n}}{120}$

A preliminary skin hydration value measurement is taken after a15-minute “dryout” period when the infant wears only a long T-shirt ordress and is in the supine position. The measurement is taken on theinfant's lower abdomen, in a region corresponding to the target zone ofthe diaper, using the evaporimeter for the purpose of establishing theinitial skin hydration value of the infant's skin at the diaper targetzone. If the preliminary SHV is less than 10 g/m²/hour, a diaper is thenplaced on the infant. If the preliminary SHV is greater than 10g/m²/hour, the “dryout” period is extended until a reading below 10g/m²/hour is obtained. Prior to securing the diaper on the infant, atube is positioned to direct a flow of liquid to hit the premarkedtarget zone. Once the diaper is secured, 210 milliliters of adjusted 0.9weight percent aqueous saline is added in three insults of 70milliliters each at a rate of 15 milliliters/second with a 45 seconddelay between insults.

The infant wears the diaper for 60 minutes after which the diaper isremoved and a test measurement of skin hydration is taken on the lowerabdomen corresponding to the target zone mark of the diaper. Themeasurement is taken over a 2-minute period. The used diaper is thenweighed. Relative humidity and temperature measurements can be takenwithin the diaper prior to the skin hydration measurements being taken.The test procedure is then repeated the next day for each infant usingthe diaper type (test or control) which the infant has not yet worn. Thecontrol diaper provides a standardized basis for comparing theperformance of the diaper configuration being tested and evaluated. Thecontrol diapers used in the tests performed in connection with theExamples were commercially available HUGGIES® Supreme diapers sold byKimberly-Clark Corporation.

Data is discarded for any infants which have added to the loading ofsaline solution. The value reported for the mean net SHV (grams/m² inone hour) is the arithmetic mean for all infants of the post-wear skinhydration value, taken at the lower abdomen (target zone mark), minusthe skin hydration value measured at the lower abdomen prior to placingthe diaper on the infant (after “dryout” period). A separate mean netSHV is determined for the test code diapers and the control codediapers.

The net skin hydration value is determined as follows:

Net SHV_(I) =Y−Z

Where:

Y=skin hydration value measured at target zone mark of an individualinfant

Z=baseline skin hydration value measured on the lower abdomen after“dryout” period prior to placing diaper on the infant

SHV_(I)=skin hydration value for individual infant

Then,${{Mean}\quad {Net}\quad {SHV}} = \frac{\sum\limits_{i = 1}^{N}{{Net}\quad {SHV}_{i}}}{N}$

Where:

N=number of infants in study

The percent reduction in skin hydration is determined as follows:${\% \quad {Reduction}} = \frac{\sum\limits_{i = 1}^{N}\left\lbrack {\left( {\left( {C - D} \right)/C} \right) \times 100} \right\rbrack}{N}$

Where:

C=Net SHV_(I) for control diaper code

D=Net SHV_(I) for test diaper code

N=number of infants in study

Tracer Gas Test

The Tracer Gas Test is a measure of the rate of air exchange in garmentssuch as absorbent articles and is a steady flow/steady state testdescribed generally in TAPPI JOURNAL., Volume 80, No. 9, September 1997.In general, the air exchange rate values are calculated from themeasured mass exchange within the garment. The test involves injecting atracer gas at a constant rate inside the article next to the outersurface of the torso of a mannequin while the article is secured aboutthe mannequin. Simultaneously, the concentration of the tracer gas inthe air space between the article and the mannequin is measured bywithdrawing a sample at the same constant rate as the injection. The airexchange rate is then be determined based on mass balances of the tracergas and the air within the space in question. The Tracer Gas Test iscompleted as follows:

Equipment

1. Mannequin—The test is conducted with Step 3 or Step 4 sized diapersdesigned for infants weighing from about 16 to about 28 pounds and fromabout 22 to about 37 pounds, respectively. The diapers are placed onmannequins which have the following dimensions:

Step 3

height (waist to knees) 26 centimeters

circumference at waist 42 centimeters

circumference at hips 44 centimeters

thigh circumference 22 centimeters

Step 4

height (waist to knees) 28 centimeters

circumference at waist 48 centimeters

circumference at hips 51 centimeters

thigh circumference 27 centimeters

2. A test area which is environmentally controlled to 20° C. and 50%relative humidity.

3. CO₂ Analyzer—An infrared CO₂ Analyzer auch as Model 17515Acommercially available from Vacu-Med Vacumetrics, 4483 McGrath Street#102, Ventura, Calif.

4. Rotameters—Rotameters to maintain gas flow rates such as MathesonRotameter Model TS-35 commercially available from Specialty GasesSoutheast Inc., 3496 Peachtree Parkway, Suwanee, Ga.

5. Gas Cylinders—Two gas cylinders of calibrated medical grade gas at apressure of 4 kPa from Specialty Gases Southeast Inc., 3496 PeachtreeParkway, Suwanee, Ga. The tracer gas includes 5% CO₂ and air and thecalibration gas is 100% air.

Procedure

1. Turn the CO₂ analyzer on. After it has been on for 30 minutes,calibrate the analyzer with the calibration gas and adjust the flowcontrol to achieve a flow rate of 150 cubic centimeters per minutethrough the analyzer.

2. Place the diaper to be tested on the mannequin.

3. Turn on the CO₂ tracer gas flow. The flow rate of the injected tracergas into the space between the diaper and the mannequin must be equal tothe sample flow rate through the CO₂ analyzer (150 cc/min.).

4. Measure and record the concentration (C) of the tracer gas (CO₂) inthe air space between the diaper and the mannequin every 10 seconds for20 minutes. The data over the last 10 minutes are averaged and used tocalculate the air exchange rate as follows:

Air Exchange Rate=150 cc/min*[(C _(T) −C)/(C−C _(O))]

wherein,

C_(T)=concentration of the tracer gas (5%)

C=concentration of the tracer gas in the space being measured

C_(O)=concentration of the tracer gas in the chamber environment (0.04%)

The Dry Air Exchange Rate is the air exchange rate as determinedaccording to the above procedure before the diaper has been subjected toany insults. The Wet Air Exchange Rate is the air exchange ratedetermined according to the above procedure except that once the diaperis secured to the mannequin, 180 milliliters (Step 3) or 210 milliliters(Step 4) of adjusted 0.9 weight percent aqueous saline is added in threeinsults of 60 or 70 milliliters each at a rate of 15 milliliters/secondwith a 45 second delay between insults. The Wet Air Exchange Rate/DryAir Exchange Rate ratio is determined by dividing the Wet Air ExchangeRate by the Dry Air Exchange Rate for the same sample.

C. albicans Viability Test

The C. albicans Viability Test is a measure of the effect of absorbentgarments, such as disposable diapers, on the viability of pathogenicmicroorganisms and, in particular, Candida albicans. In general, the C.albicans Viability Test involves inoculating delineated sites of eachvolar forearm of test subjects with a known suspension of C. albicanscells, covering the sites with full thickness patch from the absorbentgarment, and determining the viability after a 24 hour period.

A full thickness test sample patch having a length of about 5centimeters and a width of about 5 centimeters is cut from the targetzone of each product to be tested. The target zone is generally thatportion of the product intended to receive urine discharge from thewearer and typically includes portions of the intermediate and frontwaist sections of the product somewhat forward of the lateral centerlineof the product. In a typical diaper configuration, the full thicknesstest sample patch includes the topsheet, absorbent body, backsheet andany intervening layers. Approximately 15 milliliters of a 0.9 weightpercent saline solution is added to the test sample patch and allowed tosoak in for 2 minutes before the samples are placed on the forearms ofthe test subjects. A test site area of about 6.15 square centimeters ismarked on each of the test subject's volar forearms. Approximately 0.01milliliters of a 0.9 weight percent saline solution containing a knownsuspension of C. albicans cells is delivered to the test site withmicropipettes and the suspension is then spread uniformly across thetest site. After air drying, the test site is covered with the testsample patch which is secured in position using adhesive tape completelysurrounding the sample.

After 24 hours, the test sample patches are removed and a quantitativeculture is obtained from the test site using the detergent scrub methodset forth in “A New Method For Quantitative Investigation of CutaneousBacteria”, P. Williamson and A. M. Klingman, Journal of InvestigativeDermatology, 45:498-503, 1965, the disclosure of which is herebyincorporated by reference. Briefly, a sterile glass cylinderencompassing an area of 6.15 square centimeters is centered over thetest site and held firmly to the skin. One milliliter of 0.1 weightpercent Triton-x-100 in 0.075M phosphate buffer having a pH of 7.9 ispipetted into the glass cylinder and the area scrubbed for one minuteusing a sterile Teflon rod. The fluid is aspirated with a sterilepipette and a second milliliter of 0.1 weight percent Triton-x-100 in0.075M phosphate buffer having a pH of 7.9 is added to the glasscylinder. The scrub step is repeated and the two washes are pooled. Eachpooled sample is diluted in ten-fold steps with of 0.05 weight percentTriton-x-100 in 0.0375M phosphate buffer having a pH of 7.9. A 0.01milliliter aliquot of each dilution is inoculated onto Sabourands agarcontaining antibiotics. Duplicate cultures are prepared and incubated atroom temperature for 48 hours.

After incubation, the number of colony forming units are counted usingstandard microbiological methods. The C. albicans viability under apatch of the test sample can then be compared to the C. albicansviability under a control patch from a conventional absorbent articlehaving a nonbreathable outer cover, i.e. an outer cover having a WVTR ofless than 100 grams per square meter per 24 hours, such as the diaperdescribed below in connection with Comparative Example 4.

Skin Temperature Test

Skin temperature values can be determined by employing the followingtest procedure. The test is conducted on the bare forearm of adult humanbeings who have no lotions, powders or ointments on the skin and have noskin disorders. The subjects also have not been bathed, swam, smoked,exercised or consumed caffeine within 2 hours prior to and during thetest. Each subject tests two articles such as diapers during each testsession. The test diapers may include a test code and a control codesuch as the code identified in Comparative Example 6. The test diapers(test code and control code) are randomized and are conventional Step 3sized diapers, i.e. for infants weighing 16-28 pounds.

Each test diaper is weighed before and after use to verify the volume ofliquid added into the diaper. A pen is employed to mark a 1″×1″ squareat the target zone on the inside and outside of the diaper, with thecenter of the square positioned 6.0 inches below the top front edge ofthe diaper and centered side-to-side. The temperature and humiditymeasurements are taken with a temperature sensor, such as a thermocoupleprobe with vinyl insulated 10-kt gold-plated disc sensor distributed byCole-Parmer, a business having offices located in Vemon Hills, Ill.under the trade designation P-08506-80 which is attached to aDigi-Sense® Temperature/Humidity Logger distributed by Cole-Parmer, abusiness having office located in Vemon Hills, Ill. under the tradedesignation Model #91090-00. The thermocouple probe is calibrated to apre-calibrated probe (3700-52) built into the data logger. The skintemperature measurements are taken continuously once per minute.

Upon arrival, each test subject is subjected to a 15 minute acclimationperiod in a controlled environment at 40% relative humidity and 71° F.One temperature sensor is attached to each forearm, approximately midwaybetween the wrist and elbow. The lead of the sensor is placed towardsthe elbow and the sensor is secured in place with a piece of tape suchas Steri-Strip suture tape (0.25″×1.5″) commercially available from 3Mon top of the sensor and another piece of tape to hold the sensor leadin place. Baseline skin temperatures are recorded for a period of 5minutes (5 minute total test time) without a diaper attached to theforearm.

The sample diapers are then attached to respective forearms of each testsubject such that the 1″×1″ target zones on the diaper are located overthe temperature sensor. Prior to securing the diapers on the forearms ofthe subject, a fluid dispenser nozzle, acclimated to room temperature,is positioned in each diaper above the temperature sensor to direct aflow of liquid to hit the premarked target zone. Each diaper does notoverlap at the target zone and is secured in place by fastening maskingtape which fastens the upper and lower portions of the diaper togetherwithout contacting the skin of the wearer. A size 3 elastic stockinetretainer commercially available from Glenwood, Inc. is placed over theentire diaper and forearm. Once the diapers are secured, dry diaper skintemperature is recorded for 5 minutes.

The diapers are then loaded with 180 milliliters of body temperatureadjusted 0.9 weight percent aqueous saline is added in three insults of60 milliliters each at a rate of 15 milliliters/second with a 45 seconddelay between insults. The fluid dispenser nozzle is removed from eachdiaper. The subject wears each diaper for 120 additional minutes whileskin temperature readings are recorded every minute. The diapers arethen removed and weighed.

The value reported for the skin temperature is the arithmetic mean forall subjects at the specific time during the testing period for eachsample. The Wet Skin Temperature/Dry Skin Temperature ratio is thendetermined by dividing the skin temperature value after 120 minutes ofwearing the wetted sample (130 minute total test time) by the skintemperature value after 5 minutes of wearing the dry sample (10 minutetotal test time).

Z-Direction Lotion Migration Test

This test determines the quantity of lotion which remains on the targetarea of the bodyfacing surface of an absorbent article after a givenperiod of time at a given temperature. Specifically, the purpose of thetest is to compare the amount of lotion present in the target zone onarticles stored at a lower temperature with that present on articlesstored at a higher temperature. The test simulates storage at elevatedtemperature conditions which may occur to such articles. For example,such articles may be stored in the trunk of a vehicle or in a warehousein a warm climate such as in a warehouse in Arizona in July or August.The z-direction migration loss is a measure of the lotion migrationafter storage at 130° F. when compared to the lotion migration at 73° F.after a fixed period of time. Thus, this test predicts the amount oflotion which will be available on the bodyfacing surface of the articlefor transfer to the skin when the article is used as well as how quicklyit will undesirably migrate away from or along the bodyfacing surface ofthe article in use.

Specifically, the test is conducted as follows:

1. Ten (10) products having a lotion formulation applied to the topsheetor bodyside liner are obtained.

2. Five (5) products are placed in a controlled environment at atemperature of 73° F. and a relative humidity of 50% for a fixed periodof time such as, for example, 28 days. The other five (5) products areplaced in a controlled environment at a temperature of 130° F. andambient humidity for the same period of time.

3. The products are removed from the controlled environment and a sampleof the topsheet having a width of 3.75 inches and a length of 13 inchesis removed from the center of each product.

4. The samples are then subjected to Soxhlet Extraction with GravimetricAnalysis (SEGA) as follows. A SEGA test apparatus such as thatrepresentatively illustrated in FIG. 8 is used. The test apparatus 160includes a reboiler 162, chloroform vapor duct 164, cold water condenser166, holding tank 168 where the samples are placed and a chloroformrecycle duct 170. The components of the test apparatus are conventionalglassware well known to those skilled in the art. For example, thereboiler may include a 250 ml round bottom flask and the vapor duct caninclude an 85 ml soxlet. A sample is placed in the holding tank 168 andsubjected to chloroform washing cycles for 2.5 hours. 125 milliliters ofliquid chloroform is placed in the reboiler. The chloroform vaporizesand rises up through the vapor duct 164 into the condenser 166 havingtap water therein which, in turn, causes the chloroform to liquefy andfall into the holding tank 168 with the sample. The chloroform dissolvesthe lotion from the liner sample. When the liquid chloroform reaches ahigh enough level, the recycle duct returns the chloroform/lotionmixture to the reboiler. The temperature in the reboiler is controlledsuch that it is above the boiling point of the chloroform but below thatof the lotion such that only the chloroform vaporizes to start theprocess over again. One complete wash cycle takes approximately 15minutes with about 75 milliliters of chloroform circulating through theliner sample in each cycle. Upon completion, the chloroform in theevaporator is evaporated utilizing a conventional vacuum evaporator suchas a rotovap commercially available under the model number Buchi 011 RE121 for a period of 4 minutes followed by placing the lotion in analuminum pan and heating on a hot plate with forced air circulation foran additional 30 minutes.

5. The residue (lotion) remaining for each sample is then weighed. Theamount of lotion recovered from the products stored at 73° F. is thencompared to the amount of lotion recovered from the products stored at130° F. to determine the stability of the lotion formulation at hightemperature.

The z-direction migration loss of the absorbent article is thendetermined as follows:

Z-direction migration loss (%)=[(L ₇₃ −L ₁₃₀)/L ₇₃]×100

wherein,

L₇₃=average weight (g) of lotion recovered per sample stored at 73° F.

L₁₃₀=average weight (g) of lotion recovered per sample stored at 130° F.

CD-Direction Lotion Migration Test

This test determines the quantity of lotion which remains on thespecific location where it is applied on the bodyfacing surface of anabsorbent article after a given period of time at a given temperature.Specifically, the purpose of the test is to compare the amount of lotionpresent in the applied location on the topsheet or bodyside liner withthat present on the remaining portions of the topsheet of the articlesafter being stored at an elevated temperature. The test simulatesstorage at elevated temperature conditions which may occur to sucharticles. For example, such articles may be stored in the trunk of avehicle or in a warehouse in a warm climate such as in a warehouse inArizona in July or August. The cd-direction migration loss is a measureof the lateral lotion migration along the bodyfacing surface of thearticle after storage at 130° F. after a fixed period of time. Thus,this test predicts the amount of lotion which will be available in thedesired location on the bodyfacing surface of the article for transferto the skin when the article is used as well as how quickly it willundesirably migrate away from or along the bodyfacing surface of thearticle in use.

Specifically, the test is conducted as follows:

1. Five (5) products having a lotion formulation applied to the topsheetin a specific pattern are obtained.

2. The products are placed in a controlled environment at a temperatureof 130° F. and ambient humidity for a fixed period of time such as, forexample, 28 days.

3. The products are removed from the controlled environment and thetopsheet on each product is removed and dissected to remove the portionof the topsheet to which the lotion was actually applied. For example,if the lotion was applied as 4 continuous lines having a width of 0.25inches with spaces of 0.75 inches in between, the 4 strips of topsheetwould be removed.

4. The samples which include the portions of the topsheet to which thelotion was applied are then grouped together and subjected to SoxhletExtraction with Gravimetric Analysis (SEGA) as described above. Theremaining portions of the topsheet are also grouped together andsubjected to a separate SEGA extraction.

5. The residue (lotion) remaining for each group is then weighed. Theamount of lotion recovered from the portions of the topsheet to whichthe lotion was applied is then compared to the amount of lotionrecovered from the remaining portions of the topsheet to determine thestability of the lotion formulation at high temperature.

The cda direction migration loss of the absorbent article is thendetermined as follows:

CD-direction migration loss (%)=[L _(sp)/(L _(a) +L _(sp))]×100

wherein,

L_(sp)=average weight (g) of lotion recovered from the portions of thetopsheet to which the lotion was not applied per diaper

L_(a)=average weight (g) of lotion recovered from the portions of thetopsheet to which the lotion was applied per diaper

The following examples are presented to provide a more detailedunderstanding of the invention. The specific materials and parametersare exemplary and are not intended to specifically limit the scope ofthe invention.

EXAMPLES Example 1

Disposable diapers having the same general construction as the HUGGIES®Supreme Step 3 diapers described in connection with Comparative Example2 below were hand made and tested. The diapers were substantially thesame as the Supreme diapers except that the backsheet, absorbent core,surge layer and elasticized legbands of the diapers were replaced ormodified and a ventilation layer was added between the backsheet and theabsorbent core.

In the tested diapers, the backsheet included a microporousfilm/nonwoven laminate material comprising a spunbond nonwoven materiallaminated to a microporous film. The spunbond nonwoven comprisedfilaments of about 1.8 denier extruded from a copolymer of ethylene withabout 3.5 weight percent propylene and defined a basis weight of fromabout 20 grams per square meter. The film comprised a cast coextrudedfilm having calcium carbonate particles therein and defined a basisweight of about 58 grams per square meter prior to stretching. The filmwas preheated, stretched and annealed to form the micropores and thenlaminated to the spunbond nonwoven material. The resulting microporousfilm/nonwoven laminate based material had a basis weight of 45 grams persquare meter and a water vapor transmission rate of about 4000 grams persquare meter per 24 hours. Examples of such film/nonwoven laminatematerials are described in more detail in U.S. patent application Ser.No. 08/882,712 filed Jun. 25, 1997, in the name of McCormack et al. andentitled “LOW GAUGE FILMS AND FILM/NONWOVEN LAMINATES”, the disclosureof which has been incorporated by reference.

The absorbent core in the tested diapers was a dual layer absorbenthaving the general configuration set forth in FIGS. 5 and 6 except thatthere were no holes or apertures through either layer of the absorbent.The absorbent core included an upper layer and a lower layer with theupper layer extending from the front edge of the absorbent core to alocation about two thirds of the total length of the absorbent core. Theabsorbent core included from about 10 to about 11 grams of wood pulpfibers and from about 10 to about 11 grams of superabsorbent materialand, accordingly, included about 50 weight percent wood pulp fibers andabout 50 weight percent superabsorbent material. The lower layer had abasis weight of about 230 grams per square meter and the upper layer hada basis weight of about 560 grams per square meter to provide a totalbasis weight of about 790 grams per square meter in the front section ofthe core and a basis weight of about 230 grams per square meter in theback section of the core. The absorbent core further defined a width inthe crotch section of about 6.35 centimeters.

The surge layer was located between the absorbent core and the topsheetand was the same material as the surge layer in the Supreme diapersdescribed in Comparative Example 2 except that it was modified to becoextensive with the absorbent core. The diapers also included aventilation layer between the absorbent core and the backsheet of thediaper. The ventilation layer was made of the same material as the surgelayer and was also coextensive with the absorbent core. The diapers alsoincluded an elasticized leg band assembly along about two thirds of thelength of each longitudinal side edge of the diaper. The assembly hadsix (6) strands of elastomeric material laminated to a breathable,nonwoven fabric layer. The elastic strands were composed of LYCRA®elastomer aligned along the longitudinal length of the diaper toelasticize and gather the diaper legbands.

Four samples of the diapers were subjected to the Tracer Gas Test setforth above. The results are set forth in Table 1 below.

Example 2

Disposable diapers having the same general construction as the diapersdescribed in connection with Example 1 were hand made and tested. Thediapers were substantially the same as the Example 1 diapers except thatthe absorbent body was modified to include a plurality of holestherethrough in the region where the upper layer overlaid the lowerlayer as illustrated in FIGS. 5 and 6. The holes had a diameter of 1.27centimeters to provide an open area of about 12 percent based on a totalsurface area of the absorbent body. Four samples of the diapers weresubjected to the Tracer Gas Test set forth above. The results are setforth in Table 1 below.

Example 3

Disposable diapers having the same general construction as the diapersdescribed in connection with Example 2 were hand made and tested. Thediapers were substantially the same as the Example 2 diapers except thatthe ventilation layer between the absorbent body and the backsheet wasremoved. Four samples of the diapers were subjected to the Tracer GasTest set forth above. The results are set forth in Table 1 below.

Example 4

Disposable diapers having the same general construction as the diapersdescribed in connection with Example 2 were hand made and tested. Thediapers were substantially the same as the Example 2 diapers except thatthe holes in the absorbent body had a diameter of 2.54 centimeters whichalso defined an open are of about 12 percent of the total surface are ofthe absorbent body. Four samples of the diapers were subjected to theTracer Gas Test set forth above. The results are set forth in Table 1below.

Example 5

Disposable diapers having the same general construction as the diapersdescribed in connection with Example 2 were hand made and tested. Thediapers were substantially the same as the Example 2 diapers except thatthe layered absorbent body was replaced with a non-layered absorbentbody which included about 62 weight percent wood pulp fibers and about38 weight percent superabsorbent and defined a basis weight in the frontsection of about 750 to about 850 grams per square meter and a basisweight in the back section of about 375 to about 425 grams per squaremeter. Four samples of the diapers were subjected to the Tracer Gas Testset forth above. The results are set forth in Table 1 below.

Example 6

Disposable diapers having the same general construction as the diapersdescribed in connection with Example 2 were hand made and tested. Thediapers were substantially the same as the Example 2 diapers except thatthe dual layered absorbent core was replaced with a laminate whichincluded about 80 weight percent superabsorbent material commerciallyavailable from Stockhausen under the trade designation FAVOR SXM 880overwrapped by a tissue layer of cellulosic fibers having a basis weightof about 26 grams per square meter. The absorbent body also includedapertures therethrough having a diameter of 1.27 centimeters to providean open area of about 12 percent of the total surface area of theabsorbent body. Four samples of the diapers were subjected to the TracerGas Test set forth above. The results are set forth in Table 1 below.

Example 7

Disposable diapers having the same general construction as the diapersdescribed in connection with Example 2 were hand made and tested. Thediapers were substantially the same as the Example 2 diapers except thatthe absorbent body was replaced with a laminate which included about 80weight percent superabsorbent material commercially available fromStockhausen under the trade designation FAVOR SXM 880 overwrapped by atissue layer of cellulosic fibers having a basis weight of about 26grams per square meter. The laminate was provided in four segments asrepresentatively illustrated in FIGS. 3 and 4 which resulted in an openarea for the absorbent body of about 40 percent of a total surface areaof the absorbent body. Four samples of the diapers were subjected to theTracer Gas Test set forth above. The results are set forth in Table 1below.

Example 8

Disposable diapers having the same general construction as the diapersdescribed in connection with Example 2 were hand made and tested. Thediapers were substantially the same as the Example 2 diapers except thatthe backsheet was modified to define a water vapor transmission rate ofabout 1870 grams per square meter per 24 hours. Four samples of thediapers were subjected to the Tracer Gas Test set forth above. Theresults are set forth in Table 1 below.

Comparative Example 1

Disposable diapers having the same general construction as the SupremeStep 3 diapers as described in connection with Example 2 were hand madeand tested. The diapers were substantially the same as the Example 2diapers except that the backsheet was replaced with a 1 mil thickpolyethylene film material having a water vapor transmission rate ofless than 100 grams per square meter per hour. Four samples of thediapers were subjected to the Tracer Gas Test set forth above. Theresults are set forth in Table 1 below.

Comparative Example 2

Disposable diapers having the same general construction as those diaperscommercially available from Kimberly-Clark Corporation under the tradedesignation HUGGIES® Supreme Step 3 were tested.

In essence, the Supreme diapers comprised an absorbent core consistingof a mixture of wood pulp fibers and superabsorbent material surroundedby a two piece cellulosic wrapsheet having a basis weight of about 16-21grams per square meter. The absorbent core included from about 12.5 toabout 13.5 grams of airlaid wood pulp fibers and from about 7.0 to about8.5 grams of superabsorbent material. The superabsorbent material waspurchased from Stockhausen under the trade designation FAVOR SXM 880.The superabsorbent material was homogeneously mixed with the pulp fibersto form a unitary layer having a density within the range of 0.25 to0.35 grams per cubic centimeter. The homogeneous mixture of thesuperabsorbent material and the wood pulp fibers was zoned along themachine direction to provide a basis weight of from about 600 to about700 grams per square meter in the front section of the absorbent coreand a basis weight of from about 300 to about 350 grams per square meterin the back section of the absorbent core.

The Supreme diapers further included a composite backsheet comprising avapor-permeable barrier layer adhesively laminated to aspunbond/meltblown/spunbond laminate material (hereinafter “SMS”). TheSMS material had a basis weight of about 27 grams per square meter. Thevapor-permeable barrier layer consisted of a polyolefin film which had athickness of about 0.7 mil. and a basis weight of about 19.5 grams persquare meter. The polyolefin film material was commercially availablefrom Exxon Chemical Patents Incorporated, under the tradename EXXAIRE.The vapor-permeable barrier layer was adhered to the SMS laminate andpositioned between the absorbent core and the SMS laminate material ofthe backsheet. The backsheet had a water vapor transmission rate ofabout 1500 grams per square meter per 24 hours. The absorbent core wassandwiched between the backsheet and a topsheet composed of a spunbondweb of polypropylene fibers having a basis weight of about 17 grams persquare meter. A surge management layer composed of a bonded carded webwas located between the topsheet and the absorbent core. The surge layerincluded bicomponent fibers and defined an overall basis weight of about83 grams per square meter. The surge layer was a homogeneous blendcomposed of about 60 weight percent polyethylene/polyester (PE/PET),sheath-core bicomponent fibers which had a fiber denier of about 3 d andabout 40 weight percent single component polyester fibers which had afiber denier of about 6 d and which have fiber lengths of from about 3.8to about 5.08 centimeters. The surge layer further defined a width ofabout 10.2 centimeters and a length of about 16.5 centimeters. The frontedge of the surge layer was located 5.1 centimeters from the front edgeof the absorbent core.

The Supreme diapers further included a single component elasticizedwaistband and waist flap assembly at each longitudinal end of thediaper. The assembly had multiple strands of elastomeric materialsandwiched and laminated between a polymer film layer and a nonwovenfabric layer. The polymer film was a 0.00075 inch thick film composed ofa blend of a linear low density polyethylene and an ultra low densitypolyethylene. The nonwoven fabric layer was composed of a 20 grams persquare meter web of polypropylene spunbond. The elastic strands werecomposed of about 8-16 strands of LYCRA® elastomer aligned along thecross-direction of the diaper to elasticize and gather the diaperwaistbands and the internal waist flaps. The Supreme diapers alsoincluded length-wise containment flaps which extend the full length ofthe diaper and elasticized leg bands along each longitudinal side edgeof the diaper. The elastic strands in the leg band and containment flapswere composed of LYCRA® elastomer aligned along the longitudinal lengthof the diaper to elasticize and gather the diaper legbands and thecontainment flaps.

Four samples of the diapers were subjected to the Tracer Gas Test setforth above. The results are set forth in Table 1 below.

TABLE 1 Wet/ Mean Dry Air Exc. Mean Wet Air Exc. Dry Rate (cm³/min.)Rate (cm³/min.) Ratio Example 1 822 224 0.27 Example 2 794 310 0.39Example 3 679 220 0.32 Example 4 1050 360 0.34 Example 5 758 190 0.25Example 6 724 240 0.33 Example 7 677 153 0.23 Example 8 495 316 0.63Comparative Ex. 1 51 110 2.16 Comparative Ex. 2 513 171 0.33

The test results from Examples 1-8 and Comparative Examples 1 and 2indicate that diapers made according to the present invention generallyhave improved levels of air exchange both when dry and when wet whencompared to conventional diapers.

Example 9

Four samples of diapers having the same general construction as thediapers described in connection with Example 2 were hand made and testedaccording to the Skin Hydration Test set forth above. The diapers weresubstantially the same as the Example 2 diapers except that the diaperswere similar in size to commercially available Step 4 size diapers, theabsorbent body was a single layer having the same thickness throughout,and the apertures had a diameter of 2.54 centimeters. The diapersdefined an average Skin Hydration Value of 8.1 grams per square meterper hour. The results are also set forth in Table 2 below.

Example 10

Four samples of diapers having the same general construction as thediapers described in connection with Example 6 were hand made and testedaccording to the Skin Hydration Test set forth above. The diapers weresubstantially the same as the Example 6 diapers except that the diaperswere similar in size to commercially available Step 4 size diapers, theabsorbent body defined a basis weight of about 560 grams per squaremeter and the apertures had a diameter of 2.54 centimeters. The diapersdefined an average Skin Hydration Value of 2.8 grams per square meterper hour. The results are also set forth in Table 2 below.

Example 11

Four samples of diapers having the same general construction as thediapers described in connection with Example 7 were hand made and testedaccording to the Skin Hydration Test set forth above. The diapers weresubstantially the same as the Example 7 diapers except that the diaperswere similar in size to commercially available Step 4 size diapers. Thediapers defined an average Skin Hydration Value of 1.6 grams per squaremeter per hour. The results are also set forth in Table 2 below.

Comparative Example 3

Disposable diapers having the same general construction as those diaperscommercially available from Kimberly-Clark Corporation under the tradedesignation HUGGIES® Supreme Step 4 were tested. In essence, the Step 4sized Supreme diapers were similar to the Step 3 sized Supreme diapersdescribed above in connection with Comparative Example 2 except that thesize of the materials was greater.

Four samples of the diapers were subjected to the Skin Hydration Testset forth above. The diapers defined an average Skin Hydration Value of19.3 grams per square meter per hour. The results are also set forth inTable 2 below.

TABLE 2 Skin Hydration Value (g/m²/hr) Example 9 8.1 Example 10 2.8Example 11 1.6 Comparative Ex. 3 19.3

The test results from Examples 9-11 and Comparative Example 3 indicatethat diapers made according to the teachings of the present inventionexhibit significantly improved Skin Hydration Values when compared toconventional diapers. Specifically, diapers made according to thepresent invention exhibited a 58 to 92 percent reduction in the SkinHydration Value. While some reduction in the Skin Hydration Value wasanticipated due to the increased amount of air exchange within thediapers, the magnitude of the reduction was unexpected.

Example 12

Samples of diapers having the same general construction as the diapersdescribed in connection with Comparative Example 2 were hand made andtested. The diapers were substantially the same as the ComparativeExample 2 diapers except that the backsheet was modified to define awater vapor transmission rate of about 3000 grams per square meter per24 hours. The diapers were subjected to the C. albicans Viability Testset forth above. The samples of Example 12 and Comparative Example 4(control) were tested on the volar forearms of each of seven testsubjects. Approximately 0.01 milliliters of a 0.9 weight percent salinesolution containing a suspension of 5.71 log of C. albicans colonyforming units was delivered to the test site with micropipettes and thesuspension was then spread uniformly across the test site. The samplediapers according to this example defined a mean C. albicans viabilityof 1.96 log of C. albicans colony forming units. Accordingly, comparedto the mean C. albicans viability of the control (Comparative Example4), the diapers according to this example defined a reduction in the C.albicans viability value of 26 percent.

Example 13

Samples of diapers having the same general construction as the diapersdescribed in connection with Example 2 except that the backsheet definesa water vapor transmission rate of about 5000 grams per square meter per24 hours are made. The diapers are subjected to the C. albicansViability Test set forth above. The samples of Example 13 andComparative Example 4 (control) are tested on the volar forearms of eachof seven test subjects. Approximately 0.01 milliliters of a 0.9 weightpercent saline solution containing a suspension of 5.71 log of C.albicans colony forming units is delivered to the test site withmicropipettes and the suspension is then spread uniformly across thetest site. It is anticipated that the sample diapers according to thisexample would define a mean C. albicans viability of more likely lessthan 1.75 and likely less than 1.50 log of C. albicans colony formingunits. Accordingly, compared to the mean C. albicans viability of thecontrol (Comparative Example 4), it is anticipated that the diapersaccording to this example will define a reduction in the C. albicansviability value of more likely about 34 percent and likely about 43percent.

Comparative Example 4

Samples of diapers having the same general construction as the diapersdescribed in connection with Comparative Example 2 were hand made andtested. The diapers were substantially the same as the ComparativeExample 2 diapers except the backsheet was replaced with a 1.0 mil thickpolyethylene film material having a water vapor transmission rate ofless than 100 grams per square meter per 24 hours. The diapers weresubjected to the C. albicans Viability Test set forth above on the volarforearms of each of seven test subjects. Approximately 0.01 millilitersof a 0.9 weight percent saline solution containing a suspension of 5.71log of C. albicans colony forming units was delivered to the test sitewith micropipettes and the suspension was then spread uniformly acrossthe test site. The sample diapers according to this example defined amean C. albicans viability of 2.65 log of C. albicans colony formingunits.

Example 14

Samples of diapers having the same general construction as the diapersdescribed in connection with Example 13 were machine made and tested. Inparticular, the backsheet of the diapers defined a water vaportransmission rate of about 5000 grams per square meter per 24 hours. Thediapers were subjected to the C. albicans Viability Test set forthabove. The samples of Example 14 and Comparative Example 5 (control)were tested on the volar forearms of each of twenty test subjects.Approximately 0.01 milliliters of a 0.9 weight percent saline solutioncontaining a suspension of 4.92 log of C. albicans colony forming unitswas delivered to the test site with micropipettes and the suspension wasthen spread uniformly across the test site. The sample diapers accordingto this example defined a mean C. albicans viability of 1.26 log of C.albicans colony forming units. Accordingly, compared to the mean C.albicans viability of the control (Comparative Example 5), the diapersaccording to this example defined a reduction in the C. albicansviability value of 61 percent.

Comparative Examgle 5

Samples of diapers having the same general construction as the diapersdescribed in connection with Comparative Example 4 were machine made andtested. In particular, the backsheet of the diapers included a 1.0 milthick polyethylene film material having a water vapor transmission rateof less than 100 grams per square meter per 24 hours. The diapers weresubjected to the C. albicans Viability Test set forth above on the volarforearms of each of twenty test subjects. Approximately 0.01 millilitersof a 0.9 weight percent saline solution containing a suspension of 4.92log of C. albicans colony forming units was delivered to the test sitewith micropipettes and the suspension was then spread uniformly acrossthe test site. The sample diapers according to this example defined amean C. albicans viability of 3.26 log of C. albicans colony formingunits.

The test results from Examples 12 and 14 and the expected results fromExample 13 show that diapers made according to the present inventionexhibit a reduced viability and incidence of microbial infection whencompared to conventional absorbent diapers and the test results fromComparative Examples 4 and 5. It is clear that such reduced microbialviability is achieved by reducing the occlusion of the skin byincreasing the breathability of the diaper both when dry and when wet.

Example 15

Samples of diapers having the same general construction as the diapersdescribed in connection with Example 2 except that the backsheet defineda water vapor transmission rate of about 5000 grams per square meter per24 hours were made. The diapers were subjected to the Skin TemperatureTest set forth above. The samples were tested on one of the forearms ofeach of eleven test subjects. The results of the test are shown in FIG.7. The sample diapers according to this example defined a Wet SkinTemperature/Dry Skin Temperature ratio of 0.970.

Comparative Example 6

Samples of diapers having the same general construction as the diapersdescribed in connection with Comparative Example 2 were made. Thediapers were substantially the same as the Comparative Example 2 diapersexcept the backsheet was replaced with a 1.0 mil thick polyethylene filmmaterial having a water vapor transmission rate of less than 100 gramsper square meter per 24 hours. The diapers were subjected to the SkinTemperature Test set forth above. The samples were tested on one of theforearms of each of eleven test subjects. The results of the test areshown in FIG. 7. The sample diapers according to this example defined aWet Skin Temperature/Dry Skin Temperature ratio of 1.014.

The test results from Example 15 as shown in FIG. 7 show that diapersmade according to the present invention are capable of maintaining amore constant, reduced skin temperature when wet when compared toconventional absorbent diapers and the test results from ComparativeExample 6. It is hypothesized that the more constant, reduced skintemperature is achieved by reducing the occlusion of the skin byincreasing the breathability of the diaper when wet. Moreover, as shownin FIG. 7, diapers made according to the present invention are capableof maintaining a skin temperature when wet which is substantially thesame as the wearer's undiapered skin temperature. Such a maintained skintemperature can result in improved comfort to the wearer.

Example 16

A lotion formulation was prepared having the following composition:

Ingredient Weight Percent Petrolatum 55.00 Ozokerite MP 145/155 F 24.80Paraffin MP 130/135 F 4.50 Microcrystalline wax W-835 4.50 Cetyl esters(synthetic spermaceti wax) 4.50 Elvax 410 6.70

The lotion formulation was prepared by heating the petrolatum to 75° C.and adding the remaining ingredients while maintaining the temperatureat 75° C. and mixing until all ingredients were melted and uniform. Thelotion formulation defined a bulk melting point of about 45° C. and amelt point viscosity at 60° C. of about 149 centipoise. The melt pointviscosity at 45° C. was beyond measuring limits.

The lotion formulation was applied to the topsheet of diaperssubstantially identical to HUGGIES® Supreme diapers commerciallyavailable from Kimberly-Clark Corporation at an add-on rate of about 0.2grams per diaper. The lotion was applied to the topsheet as a series of4 lines down the center of the diaper. Each line of lotion had a widthof 0.25 inches with a space having a width of 0.75 inches between eachline.

The diapers were subjected to the Z-direction Lotion Migration Testwhereby five diapers were stored at a temperature of 73° F. for 28 daysand five diapers were stored at a temperature of 130° F. for 28 days.The diapers defined a z-direction migration loss of 44.3%. The diaperswere also subjected to the CD-direction Lotion Migration Test wherebyfive diapers were stored at a temperature of 73° F. for 28 days and fivediapers were stored at a temperature of 130° F. for 28 days. The diapersdefined a cd-direction migration loss of 16.7%.

Comparative Example 7

Samples of PAMPERS® Premium diapers commercially available from TheProcter & Gamble Company were obtained. The diapers included a lotionformulation on the topsheet which had the following composition:

Ingredient Weight Percent Petrolatum 58.50 Stearyl Alcohol 41.50 Aloetrace

The lotion formulations defined a bulk melting point of about 52°, amelt point viscosity at 50° C. of about 10 centipoise and a melt pointviscosity of about 5 centipoise at a temperature of 60° C.

The diapers were subjected to the Z-direction Lotion Migration Testwhereby five diapers were stored at a temperature of 73° F. for 28 daysand five diapers were stored at a temperature of 130° F. for 28 days.The diapers defined a z-direction migration loss of 62%.

Comparative Example 8

Samples of PAMPERS® Rash Guard diapers commercially available from TheProcter & Gamble Company were obtained. The diapers included a lotionformulation on the topsheet which had the following composition:

Ingredient Weight Percent Petrolatum 58.50 Stearyl Alcohol 41.50

The lotion formulations defined a bulk melting point of about 52°, amelt point viscosity at 50° C. of about 10 centipoise and a melt pointviscosity of about 5 centipoise at a temperature of 60° C.

The diapers were subjected to the Z-direction Lotion Migration Testwhereby five diapers were stored at a temperature of 73° F. for 28 daysand five diapers were stored at a temperature of 130° F. for 28 days.The diapers defined a z-direction migration loss of 66%.

Comparative Example 9

A lotion formulation was prepared having the following composition:

Ingredient Weight Percent Petrolatum 80.00 Stearyl Alcohol 20.00

The lotion formulation was prepared by heating the petrolatum to 75° C.and adding the stearyl alcohol while maintaining the temperature at 75°C. and mixing until all ingredients were melted and uniform. The lotionformulation defined a bulk melting point of about 52° C. and a meltpoint viscosity at 60° C. of about 5 centipoise.

The lotion formulation was applied to the topsheet of diaperssubstantially identical to HUGGIES® Supreme diapers commerciallyavailable from Kimberly-Clark Corporation at an add-on rate of about 0.2grams per diaper. The lotion was applied to the topsheet as a series of4 lines down the center of the diaper. Each line of lotion had a widthof 0.25 inches with a space having a width of 0.75 inches between eachline.

The diapers were subjected to the Z-direction Lotion Migration Testwhereby five diapers were stored at a temperature of 73° F. for 28 daysand five diapers were stored at a temperature of 130° F. for 28 days.The diapers defined a z-direction migration loss of 91.7%. The diaperswere also subjected to the CD-direction Lotion Migration Test wherebyfive diapers were stored at a temperature of 73° F. for 28 days and fivediapers were stored at a temperature of 130° F. for 28 days. The diapersdefined a cd-direction migration loss of 48.9%.

Comparative Example 10

A lotion formulation was prepared having the following composition:

Ingredient Weight Percent Petrolatum 52.00 Polyphenylmethyl-siloxane20.00 Paraffin Wax 15.00 Cetearyl Alcohol 10.00 PEG 2000 3.00

The lotion formulation was substantially identical to that described inExample 6 in U.S. Pat. No. 5,643,588 issued Jul. 1, 1997 to Roe et al.The lotion formulation was prepared by heating the petrolatum to 75° C.,adding the remaining ingredients while maintaining the temperature at75° C. and mixing until all ingredients were melted and uniform. Thelotion formulation defined a bulk melting point of about 54° C. and amelt point viscosity at 60° C. of about 54 centipoise.

The lotion formulation was applied to the topsheet of diaperssubstantially identical to HUGGIES® Supreme diapers commerciallyavailable from Kimberly-Clark Corporation at an add-on rate of about 0.2grams per diaper. The lotion was applied to the topsheet as a series of4 lines down the center of the diaper. Each line of lotion had a widthof 0.25 inches with a space having a width of 0.75 inches between eachline.

The diapers were subjected to the Z-direction Lotion Migration Testwhereby five diapers were stored at a temperature of 73° F. for 28 daysand five diapers were stored at a temperature of 130° F. for 28 days.The diapers defined a z-direction migration loss of 69.6%. The diaperswere also subjected to the CD-direction Lotion Migration Test wherebyfive diapers were stored at a temperature of 73° F. for 28 days and fivediapers were stored at a temperature of 130° F. for 28 days. The diapersdefined a cd-direction migration loss of 50.0%.

As representatively shown, the lotion formulations on the absorbentarticles of the different aspects of the present invention (Example 16)migrate significantly less than conventional lotion formulations such asthose of Comparative Examples 7-10 at elevated temperatures. Inparticular, the articles of Example 16 exhibited about 50% lessz-directional lotion migration and over 60% less cd-directional lotionmigration compared to the diapers in Comparative Examples 7-10. Suchreduced level of migration at elevated temperatures results in more ofthe lotion remaining on the bodyfacing surface of the article which canlead to a higher percentage of the lotion transferring to the skin ofthe wearer to improve skin health and reduce friction.

Examples 17-19

The effect of the treatment compositions of the present invention toinhibit the hydrolysis of a model protein substrate by urine and a fecalextract was determined. In addition, the ability of the treatmentcompositions to reduce a fecal extract-elicited pro-inflammatoryresponse in EpiDerm™ was measured. The treatment composition applied toa material was placed on the EpiDerm™ sample, both before and afterapplication of the fecal irritant. The release of a pro-inflammatorysignaling molecule lnterleukin-1 alpha, was compared to that of thecontrol not containing the treatment composition.

Example 17

Aqueous zinc salts were shown to inhibit a chemical reaction thatcontributes to diaper rash. The proteolytic activity of fecal extractwas measured using fluorescently labeled casein. Inhibiting emulsions ofzinc sulfate heptahydrate in water were prepared ranging from 0-1 mM.

A fecal extract sample was prepared from feces obtained from an infanton antibiotics (Sulfatrim) who had diaper rash. To prepare the extract,the feces was suspended in water and vigorously vortexed. Aftervortexing, the sample was held on ice prior to centrifugation at 15,000times the force of gravity for 20 minutes. The supernatant was filteredthrough 0.22 micron cellulose acetate filters and stored at −80° C.until use. Trypsin (molecular weight=23,500 daltons), a protease knownto contribute to diaper rash, was measured in the fecal extract at aconcentration of 5,850 picomoles/milliliter. Pancreatic elastase(molecular weight=25,000 daltons), a suspected contributor, was measuredin the fecal extract at a concentration of 83.6 picomoles/milliliter.The fecal extract (7.1 mg/ml in water) was diluted in water to 2 μg/ml.

The zinc sulfate heptahydrate (Aldrich Chemicals, Wis.) emulsions (20μL) having a molecular weight of 287.5 were added to wells of a 96 whiteplate (Dynex, Chantilly, Va.) containing 100 μL of a fecal extract andallowed to incubate for 15 minutes at room temperature. The reaction wasinitiated with the addition of 80 μL of 12.5 μg/ml solution of afluorescent dye-labeled casein substrate (EnzChek Protease Assay Kit(E-6639), Molecular Probes, Eugene, Oreg.) in 20 mM Tris-HCl, pH 8.0.Reaction of the fecal extract with the casein substrate cleaves thefluorescent dye from the substrate. Relative fluorescence units (RFUs)were collected using the Fluoroskan Ascent System (Labsystems,Incorporated, Needham Heights, Mass.) with excitation and emissionfilters of 485 and 538 nm, respectively. Data were collected each minutefor 15 minutes and rates (RFU/min) were calculated. Using theuninhibited wells as 100% protease activity, percent of fecalproteolytic activity remaining was determined for each concentration ofzinc inhibitor (Inhibited Rate/Uninhibited rate*100).

The data show that zinc effectively inhibited the hydrolysis of caseinby the fecal extract in a dose-dependent manner. A plot of the data forthe fecal extract sample is shown in FIG. 9, which is a graph showinghow the proteolytic activity of the fecal extract was reduced as thezinc sulfate heptahydrate concentration was increased. These data showthat the aqueous zinc emulsion has the ability to neutralize proteasesin feces that have been implicated to induce skin inflammation in thediaper environment (Anderson, P. H., Bucher, A. P., Saees, I., Lee, P.C., Davis, J. A., and Maibach, H. I. Faecal enzymes: in vivo skinirritation. Contact Dermatitis 1994; 30, 152-158).

Example 18

Aqueous zinc salts were shown to inhibit a chemical reaction thatcontributes to diaper rash. The proteolytic activity of infant urine wasmeasured using fluorescently-labeled casein. Inhibiting emulsions ofzinc sulfate heptahydrate in water were prepared ranging from 0-50 mM.

Two (2) infant urine (100 μL) samples were added to wells of a 96 whiteplate (Dynex) containing 80 μL of 12.5 μg/ml solution of a fluorescentdye-labeled casein substrate (EnzChek Protease Assay Kit (E-6639)) in100 mM Tris-HCl, pH 8.0, and allowed to incubate for 60 minutes at 37°C. After the incubation time, 20 μL of zinc sulfate heptahydrate inwater, ranging from 0-50 mM was added to the wells. Reaction of theinfant urine with the casein substrate cleaves the fluorescent dye fromthe substrate. RFUs were collected using the Fluoroskan Ascent Systemwith excitation and emission filters of 485 and 538 nm, respectively.Data were collected each minute for 60 minutes at 37° C. and rates(RFU/min) from 30-50 minutes were calculated for each zincconcentration. Using the uninhibited wells as 100% protease activity,percent of urine proteolytic activity remaining was determined for eachconcentration of zinc inhibitor (Inhibited Rate/Uninhibited rate*100).

The data show that zinc effectively inhibited the hydrolysis of caseinby infant urine in a dose-dependent manner. A plot of the data is shownin FIG. 10, which is a graph showing how the proteolytic activity ofinfant urine was reduced as the zinc sulfate heptahydrate concentrationwas increased. These data show that the aqueous zinc emulsion has theability to neutralize proteases in infant urine.

Example 19

Zinc sulfate heptahydrate was also shown to inhibit the reaction offecal extract with synthetic skin. The synthetic skin, EpiDerm™ 201(MatTek Corporation, Ashland, Mass.) contains keratinocytes that releaseinterleukin-1 alpha (IL-1 alpha) when subjected to proteases in thefecal extract. When the IL-1 alpha was released, it diffused from theskin into the fluid below the EpiDerm™. Samples of this fluid were takenand analyzed for the presence of the IL-1 alpha. Higher levels of IL-1alpha was indicative of greater skin irritation.

Prior to application onto the EpiDerm™, the fecal extract (10.4 μL) waspre-incubated for 30 minutes at room temperature with 250 mM zincsulfate heptahydrate in water (2.6 μL). Water only and fecal extractonly samples served as controls. After application of the samples to theEpiDerm™, 25 μL aliquots were removed from the underlying media at 8,12, and 24 hours to test for the presence of the IL-1 alpha. Thealiquots were directly added to a 1.5 mL micro-centrifuge tubecontaining 225 μL of filtered-sterilized 20 mM Tris-HCl, pH 8.0, 1% BSAbuffer and stored at −80° C. After all samples were collected, IL-1alpha levels were quantified using the R&D Systems lnterleukin-1 alphaQuantikine Kit (R&D Systems, Minneapolis, Minn.).

A plot of the data is shown in FIG. 11, which is a graph showing thatthe addition of the zinc sulfate heptahydrate (FE+zinc) reduced theamount of interleukin-1 alpha released into the underlying mediarelative to the application of the substrate treated with uninhibitedfecal extract (FE+water). A similar reduction was shown at 8, 12, and 24hours. The asterisk over the error bars in FIG. 11 represent a Studentt-test 95% confidence interval.

Re-running the same experiment with varied concentrations of zincsulfate heptahydrate (0, 25, 50, 125, and 250 mM) in the 2.6 μL aliquotadded to the 10.4 μL sample of fecal extract, demonstrated that zincsulfate heptahydrate effectively inhibits the proteolytic activity offecal extract in a dose-dependent manner. A plot of the data, shown inFIG. 12, shows that the proteolytic activity of fecal extract is reducedas the zinc sulfate heptahydrate concentration is increased.

Example 20

Skin treatment compositions of the present invention were formed bycreating an emulsion (or microemulsion) of a skin health benefit agentand water as the carrier liquid. Aqueous emulsions of zinc salt as theskin health benefit agent, AHCOVEL, as the surfactant system, andCROSILK as the silk protein, were prepared. The stable emulsions werediluted to about a 5% by weight emulsion and applied to the surface of apolyolefin nonwoven topsheet fabric via a saturation dip and squeezeprocess as follows:

Untreated polypropylene spunbond materials (basis weight of about 0.5ounces per square yard) were used as a substrate for the treatmentcompositions. The compositions were applied to the substrates by alow-solids batch treatment process. An 8 in.×12 in. (20.32×30.48 cm)example of the substrate was first dipped in an aqueous treatment bathof known composition illustrated in Table 3 below.

TABLE 3 Treatment Bath Concentration Ahcovel Crosilk Zinc SulfateExample Composition Water Base N-62 10,000 Monohydrate 1 Control 98.81.2 — — 2 1 98.146 1.2 .6 .054

The saturated examples were then nipped between two rubber rollers in alaboratory wringer, Type LW-1, No. LW-83A (Atlas Electric Devices,Chicago, Ill.), and subsequently dried in an oven at 60° C. for about 20minutes or until constant weight was obtained. Nip pressure was adjustedto achieve a 100% wet pick-up (%WPU). %WPU is calculated from thefollowing equation:

%WPU=[(Ww−Wd)/Wd]×100,

where:

Ww=wet weight of the nipped fabric,

Wd=dry weight of the treated fabric.

Knowing the bath concentration and the %WPU, the % Add On can becalculated from the following equation:

%AddOn=(%BathConcentration)×(%WPU)÷100

If, as in this example, the %WPU=100, then the % Add-On will equal the %Bath Concentration. However, other %WPU and % Bath Concentrationcombinations can be used to achieve similar results.

The treated spunbond materials were tested to assess their capacity toinhibit the reaction of fecal extract with synthetic skin. The fecalextract was prepared from feces obtained from an infant on antibiotics(Sulfatrim) who had diaper rash. To prepare the extract, the feces weresuspended in water and vigorously vortexed. After vortexing, the sampleswere held on ice prior to centrifugation at 15,000 times the force ofgravity for 20 minutes. The supernatant was filtered through 0.22 microncellulose acetate filters and stored at −70° C. until use. Trypsin(molecular weight=23,500 daltons), a protease known to contribute todiaper rash, was measured in the fecal extract at a concentration of5,850 picomoles/milliliter. Pancreatic elastase (molecular weight=25,000daltons), a suspected contributor, was measured in the fecal extract ata concentration of 83.6 picomoles/milliliter.

The synthetic skin, EpiDerm™ 201 (MatTek Corporation, Ashland, Mass.)contains keratinocytes that release interleukin-1 alpha (IL-1 alpha)when subjected to proteases such as trypsin and pancreatic elastase.When the IL-1 alpha is released, it diffuses from the skin into thefluid below the EpiDerm™. Samples of this fluid are taken and analyzedfor the presence of the IL-1 alpha. Higher levels of IL-1 alpha areindicative of greater skin irritation.

To perform the experiment, 10 μL of water was applied to the surface ofthe synthetic skin. The treated spunbond materials were cut into about0.9 cm discs which were placed on top of the water on the EpiDerm™.After about a two hour incubation at 37° C., the discs were removed andthe EpiDerm™ was insulted with 15 μL of insult fluid where each of thetreated spunbond discs had been. A second treated spunbond disc was thenplaced on top of the insult fluid to simulate the diaper environment.After 11 hours at 37° C., an aliquot from the underlying fluid bathingthe EpiDerm™ was removed and the amount of IL-1 alpha quantified usingthe R&D Systems lnterleukin-1 alpha Quantikine Kit (R&D Systems,Minneapolis, Minn.).

Four treatments were done using the two examples from Table 1 and twoinsult fluids (fecal extract and water) as shown in Table 4.

TABLE 4 EpiDerm ™ treatments Code Example Used Insult Fluid A 1(Control) Water B 1 (Control) Fecal Extract C 2 Water D 2 Fecal Extract

The results of the experiments of Table 4 are shown below in Table 5.The application of the materials treated with Crosilk and Zinc (Code Cand D) to the EpiDerm™ reduced the amount of interleukin-1 alphareleased into the underlying media relative to the application of thematerials treated with just Ahcovel (Code A and B, respectively).

TABLE 5 IL-1 alpha Released (picograms/milliliter) Standard Number ofCode Mean Deviation samples A 14.03 4.768 6 B 105 66 5 C 6.77 6.77 6 D44.92 23.4 6

Example 21

Water soluble silk protein (SERICIN, Pentapharm AG, Basel, Switzerland)and hydrolyzed silk (CROSILK 10,000, Croda, Incorporated, Parsippany,N.J.) were individually shown to inhibit proteolytic activity in thefecal extract that has been implicated to contribute to diaper rash.Serial dilutions of the neat protein and hydrolysate were performed with100 mM Tris-HCl pH 8.0 as the diluent. The silk protein concentrationswere determined using a Macro BCA Protein Assay Reagent Kit (Pierce,Rockford, Ill.),

Fecal extract was prepared as described above for the examples of silkprotein and zinc compositions. SERICIN and CROSILK (20 μL) were added towells of a 96 white plate (Dynex, Chantilly, Va.) containing 80 μL of a12.5 μg/ml solution of a fluorescent dye-labeled casein substrate(EnzChek Protease Assay Kit (E-6639), Molecular Probes, Eugene, Oreg.).The reaction was initiated with the addition of 100 μL of the 2 μg/mlfecal extract. Reaction of the fecal extract with the casein substratecleaves the fluorescent dye from the substrate. Relative fluorescenceunits (RFUs) were collected using the Fluoroskan Ascent System(Labsystems, Incorporated, Needham Heights, Mass.) with excitation andemission filters of 485 and 538 nm, respectively. The reaction was runfor 30 min. at room temperature and rates (RFU/min) from 10-20 minuteswere calculated. Percent of fecal proteolytic activity remaining wasdetermined for each concentration of SERICN and CROSILK inhibitor(Inhibited Rate/Uninhibited rate*100).

A plot of the data is shown in FIG. 13, which is a graph showingreduction of proteolytic activity with increasing concentrations of bothSERICIN and CROSILK. These data suggest that both molecules have theability to neutralize proteases in feces that have been implicated toinduce skin inflammation in the diaper environment (Faecal enzymes: invivo skin irritation, supra).

As representatively shown in Examples 17-21, the various treatmentcompositions on the topsheets of absorbent articles of the differentaspects of the present invention effectively inhibits the proteolyticactivity of fecal extracts when transferred to the skin. Such reducedlevel of proteolytic activity can result in improved skin health.

Having thus described the invention in rather full detail, it will bereadily apparent to a person of ordinary skill that various changes andmodifications can be made without departing from the spirit of theinvention. All of such changes and modifications are contemplated asbeing within the scope of the present invention as defined by thesubjoined claims.

We claim:
 1. A disposable absorbent article which defines a front waistsection, a rear waist section, and an intermediate section whichinterconnects said front and rear waist sections, said absorbent articlecomprising: a) a vapor permeable backsheet which defines a Water VaporTransmission Rate of at least about 1000 grams per square meter per 24hours calculated according to a Water Vapor Transmission Test as setforth herein; b) a liquid permeable topsheet which is positioned infacing relation with said backsheet; c) an absorbent body locatedbetween said backsheet and said topsheet; and d) a lotion formulation onat least a portion of a bodyfacing surface of said absorbent articlewhich includes from about 5 to about 95 weight percent of an emollientand from about 5 to about 95 weight percent of a wax.
 2. The absorbentarticle of claim 1 and further comprising a ventilation layer locatedbetween said backsheet and said absorbent body.
 3. The absorbent articleof claim 2 wherein said ventilation layer comprises a hydrophobic,nonwoven material having a thickness of at least about 0.10 centimetersand a basis weight of from about 20 to about 120 grams per square meter.4. The absorbent article of claim 1 and further comprising a surgemanagement layer which is located between said topsheet and saidabsorbent wherein said surge management layer comprises a nonwovenmaterial having a basis weight of from about 30 to about 120 grams persquare meter.
 5. The absorbent article of claim 1 wherein said WaterVapor Transmission Rate of said vapor permeable backsheet is at leastabout 1500 grams per square meter per 24 hours calculated according tosaid Water Vapor Transmission Test.
 6. The absorbent article of claim 1wherein said absorbent body includes zones of high air permeabilitywhich define a Frazier Porosity which is at least about 10 percentgreater than a Frazier Porosity of portions of said absorbent bodyadjacent to said zones of high air permeability.
 7. The absorbentarticle of claim 6 wherein said zones of high air permeability comprisefrom about 5 to about 75 percent of a total surface area of saidabsorbent body.
 8. The absorbent article of claim 6 wherein saidabsorbent body includes a plurality of air passageways therethrough toprovide said zones of high air permeability.
 9. The absorbent artide ofclaim 1 wherein said lotion formulation further includes from about 0.1to about 25 weight percent of a viscosity enhancer selected from thegroup consisting of polyolefin resins, polyolefin polymers,polyethylene, lipophilic/oil thickeners and mixtures thereof based on atotal weight of said lotion formulation.
 10. The absorbent articleaccording to claim 1 wherein said emollient is selected from the groupconsisting of oils, esters, glycerol esters, ethers, alkoxylatedcarboxylic acids, alkoxylated alcohols, fatty alcohols and mixturesthereof.
 11. The absorbent article according to claim 1 wherein saidemollient is a petroleum based emollient.
 12. The absorbent articleaccording to claim 1 wherein said wax is selected from the groupconsisting of animal based waxes, vegetable based waxes, mineral basedwaxes, silicone based waxes and mixtures thereof all of which may benatural or synthetic.
 13. The absorbent article according to claim 1wherein said absorbent article defines a z-direction migration loss ofno more than about 55%.
 14. The absorbent article of claim 1 whereinsaid absorbent article defines a Wet Air Exchange Rate of at least about190 cubic centimeters per minute and a Dry Air Exchange Rate of at leastabout 525 cubic centimeters per minute calculated according to saidTracer Gas Test.
 15. The absorbent article of claim 1 wherein saidabsorbent article defines a Wet Air Exchange Rate/Dry Air Exchange Rateratio of at least about 0.20 calculated according to said Tracer GasTest.
 16. The absorbent article of claim 1 wherein said absorbentarticle defines a Skin Hydration Value of less than about 18 grams persquare meter per hour calculated according to a Skin Hydration Test setforth herein.
 17. The absorbent article of claim 1 wherein saidabsorbent article defines a Skin Hydration Value of less than about 15grams per square meter per hour calculated according to a Skin HydrationTest set forth herein.
 18. The absorbent article of claim 1 wherein saidabsorbent article defines a Wet Skin Temperature/Dry Skin TemperatureRatio of no more than about 1.010 calculated according to a SkinTemperature Test set forth herein.
 19. A disposable absorbent articlecomprising an absorbent, a front waist section, a rear waist section andan intermediate section which interconnects said front and rear waistsections, said absorbent article comprising a treatment composition onat least a portion of a bodyfacing surface of said absorbent articlewhich includes: a) a surfactant; and b) a skin health benefit agent;wherein said absorbent article defines a Wet Air Exchange Rate of atleast about 190 cubic centimeters per minute calculated according to aTracer Gas Test set forth herein.
 20. The absorbent article of claim 19wherein said surfactant is selected from the group comprisingethoxylated hydrogenated fatty oils, monosaccharides, monosaccharidederivatives, polysaccharides, polysaccharide derivatives andcombinations thereof.
 21. The absorbent article of claim 19 wherein saidskin health benefit agent comprises aqueous zinc salt or zinc sulfatemonohydrate.
 22. The absorbent article of claim 21 wherein saidsurfactant and zinc salt form said treatment composition and are presentat a weight ratio of about 0.01-25 wt. % zinc salt to about 75-99.99 wt.% surfactant.
 23. The absorbent article of claim 19 wherein said skinhealth benefit agent comprises a protein.
 24. The absorbent article ofclaim 23 wherein said protein comprises a silk protein.
 25. Theabsorbent article of claim 24 wherein said silk protein comprisessericin.
 26. The absorbent article of claim 21 wherein said skin healthbenefit agent further comprises a protein.
 27. The absorbent article ofclaim 19 wherein said absorbent article defines a Dry Air Exchange Rateof at least about 525 cubic centimeters per minute calculated accordingto said Tracer Gas Test.
 28. The absorbent article of claim 19 whereinsaid Wet Air Exchange Rate is at least about 225 cubic centimeters perminute calculated according to said Tracer Gas Test.
 29. The absorbentarticle of claim 19 wherein said absorbent article defines a Wet AirExchange Rate/Dry Air Exchange Rate ratio of at least about 0.20calculated according to said Tracer Gas Test.
 30. The absorbent articleof claim 19 wherein said absorbent article defines a Skin HydrationValue of less than about 18 grams per square meter per hour calculatedaccording to a Skin Hydration Test set forth herein.
 31. The absorbentarticle of claim 19 wherein said absorbent article defines a SkinHydration Value of less than about 15 grams per square meter per hourcalculated according to a Skin Hydration Test set forth herein.
 32. Theabsorbent article of claim 19 wherein said absorbent article defines aSkin Hydration Value of less than about 12 grams per square meter perhour calculated according to a Skin Hydration Test set forth herein. 33.The absorbent article of claim 19 wherein said absorbent article definesa Wet Skin Temperature/Dry Skin Temperature Ratio of no more than about1.010 calculated according to a Skin Temperature Test set forth herein.34. The absorbent article of claim 19 wherein said absorbent articledefines a Wet Skin Temperature/Dry Skin Temperature Ratio of no morethan about 1.000 calculated according to a Skin Temperature Test setforth herein.
 35. The absorbent article of claim 19 and furthercomprising: a) a vapor permeable backsheet which defines a Water VaporTransmission Rate of at least about 1000 grams per square meter per 24hours calculated according to a Water Vapor Transmission Test as setforth herein; b) a liquid permeable topsheet which is positioned infacing relation with said backsheet; and c) an absorbent body locatedbetween said backsheet and said topsheet.
 36. The absorbent article ofclaim 35 wherein said Water Vapor Transmission Rate of said vaporpermeable backsheet is at least about 1500 grams per square meter per 24hours calculated according to said Water Vapor Transmission Test.